1
|
Huang HH, Wang YJ, Jiang HY, Yu HW, Chen YQ, Chiou A, Kuo JC. Sarcopenia-related changes in serum GLP-1 level affect myogenic differentiation. J Cachexia Sarcopenia Muscle 2024. [PMID: 38926763 DOI: 10.1002/jcsm.13524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 04/26/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Sarcopenia, a group of muscle-related disorders, leads to the gradual decline and weakening of skeletal muscle over time. Recognizing the pivotal role of gastrointestinal conditions in maintaining metabolic homeostasis within skeletal muscle, we hypothesize that the effectiveness of the myogenic programme is influenced by the levels of gastrointestinal hormones in the bloodstream, and this connection is associated with the onset of sarcopenia. METHODS We first categorized 145 individuals from the Emergency Room of Taipei Veterans General Hospital into sarcopenia and non-sarcopenia groups, following the criteria established by the Asian Working Group for Sarcopenia. A thorough examination of specific gastrointestinal hormone levels in plasma was conducted to identify the one most closely associated with sarcopenia. Techniques, including immunofluorescence, western blotting, glucose uptake assays, seahorse real-time cell metabolic analysis, flow cytometry analysis, kinesin-1 activity assays and qPCR analysis, were applied to investigate its impacts and mechanisms on myogenic differentiation. RESULTS Individuals in the sarcopenia group exhibited elevated plasma levels of glucagon-like peptide 1 (GLP-1) at 1021.5 ± 313.5 pg/mL, in contrast to non-sarcopenic individuals with levels at 351.1 ± 39.0 pg/mL (P < 0.05). Although it is typical for GLP-1 levels to rise post-meal and subsequently drop naturally, detecting higher GLP-1 levels in starving individuals with sarcopenia raised the possibility of GLP-1 influencing myogenic differentiation in skeletal muscle. Further investigation using a cell model revealed that GLP-1 (1, 10 and 100 ng/mL) dose-dependently suppressed the expression of the myogenic marker, impeding myocyte fusion and the formation of polarized myotubes during differentiation. GLP-1 significantly inhibited the activity of the microtubule motor kinesin-1, interfering with the translocation of glucose transporter 4 (GLUT4) to the cell membrane and the dispersion of mitochondria. These impairments subsequently led to a reduction in glucose uptake to 0.81 ± 0.04 fold (P < 0.01) and mitochondrial adenosine triphosphate (ATP) production from 25.24 ± 1.57 pmol/min to 18.83 ± 1.11 pmol/min (P < 0.05). Continuous exposure to GLP-1, even under insulin induction, attenuated the elevated glucose uptake. CONCLUSIONS The elevated GLP-1 levels observed in individuals with sarcopenia are associated with a reduction in myogenic differentiation. The impact of GLP-1 on both the membrane translocation of GLUT4 and the dispersion of mitochondria significantly hinders glucose uptake and the production of mitochondrial ATP necessary for the myogenic programme. These findings point us towards strategies to establish the muscle-gut axis, particularly in the context of sarcopenia. Additionally, these results present the potential of identifying relevant diagnostic biomarkers.
Collapse
Affiliation(s)
- Hsien-Hao Huang
- Department of Emergency Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Emergency and Critical Care Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yun-Jie Wang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hui-Yu Jiang
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Helen Wenshin Yu
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yin-Quan Chen
- Cancer and Immunology Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Arthur Chiou
- Institute of Biophotonics, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Jean-Cheng Kuo
- Institute of Biochemistry and Molecular Biology, National Yang Ming Chiao Tung University, Taipei, Taiwan
- Cancer and Immunology Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
| |
Collapse
|
2
|
Shilleh AH, Viloria K, Broichhagen J, Campbell JE, Hodson DJ. GLP1R and GIPR expression and signaling in pancreatic alpha cells, beta cells and delta cells. Peptides 2024; 175:171179. [PMID: 38360354 DOI: 10.1016/j.peptides.2024.171179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/17/2024]
Abstract
Glucagon-like peptide-1 receptor (GLP1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are transmembrane receptors involved in insulin, glucagon and somatostatin secretion from the pancreatic islet. Therapeutic targeting of GLP1R and GIPR restores blood glucose levels in part by influencing beta cell, alpha cell and delta cell function. Despite the importance of the incretin-mimetics for diabetes therapy, our understanding of GLP1R and GIPR expression patterns and signaling within the islet remain incomplete. Here, we present the evidence for GLP1R and GIPR expression in the major islet cell types, before addressing signaling pathway(s) engaged, as well as their influence on cell survival and function. While GLP1R is largely a beta cell-specific marker within the islet, GIPR is expressed in alpha cells, beta cells, and (possibly) delta cells. GLP1R and GIPR engage Gs-coupled pathways in most settings, although the exact outcome on hormone release depends on paracrine communication and promiscuous signaling. Biased agonism away from beta-arrestin is an emerging concept for improving therapeutic efficacy, and is also relevant for GLP1R/GIPR dual agonism. Lastly, dual agonists exert multiple effects on islet function through GIPR > GLP1R imbalance, increased GLP1R surface expression and cAMP signaling, as well as beneficial alpha cell-beta cell-delta cell crosstalk.
Collapse
Affiliation(s)
- Ali H Shilleh
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Katrina Viloria
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Jonathan E Campbell
- Duke Molecular Physiology Institute, USA; Department of Medicine, Division of Endocrinology, Duke University, Durham, NC, USA; Department of Pharmacology and Cancer Biology, Duke University, Durham, NC, USA.
| | - David J Hodson
- Oxford Centre for Diabetes, Endocrinology and Metabolism (OCDEM), NIHR Oxford Biomedical Research Centre, Churchill Hospital, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
| |
Collapse
|
3
|
Qiao L, Lu C, Zang T, Dzyuba B, Shao J. Maternal GLP-1 receptor activation inhibits fetal growth. Am J Physiol Endocrinol Metab 2024; 326:E268-E276. [PMID: 38197791 PMCID: PMC11193516 DOI: 10.1152/ajpendo.00361.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/03/2024] [Accepted: 01/03/2024] [Indexed: 01/11/2024]
Abstract
Glucagon-like peptide 1 (GLP-1) regulates food intake, insulin production, and metabolism. Our recent study demonstrated that pancreatic α-cells-secreted (intraislet) GLP-1 effectively promotes maternal insulin secretion and metabolic adaptation during pregnancy. However, the role of circulating GLP-1 in maternal energy metabolism remains largely unknown. Our study aims to investigate systemic GLP-1 response to pregnancy and its regulatory effect on fetal growth. Using C57BL/6 mice, we observed a gradual decline in maternal blood GLP-1 concentrations. Subsequent administration of the GLP-1 receptor agonist semaglutide (Sem) to dams in late pregnancy revealed a modest decrease in maternal food intake during initial treatment. At the same time, no significant alterations were observed in maternal body weight or fat mass. Notably, Sem-treated dams exhibited a significant decrease in fetal body weight, which persisted even following the restoration of maternal blood glucose levels. Despite no observable change in placental weight, a marked reduction in the placenta labyrinth area from Sem-treated dams was evident. Our investigation further demonstrated a substantial decrease in the expression levels of various pivotal nutrient transporters within the placenta, including glucose transporter one and sodium-neutral amino acid transporter one, after Sem treatment. In addition, Sem injection led to a notable reduction in the capillary area, number, and surface densities within the labyrinth. These findings underscore the crucial role of modulating circulating GLP-1 levels in maternal adaptation, emphasizing the inhibitory effects of excessive GLP-1 receptor activation on both placental development and fetal growth.NEW & NOTEWORTHY Our study reveals a progressive decline in maternal blood glucagon-like peptide 1 (GLP-1) concentration. GLP-1 receptor agonist injection in late pregnancy significantly reduced fetal body weight, even after restoration of maternal blood glucose concentration. GLP-1 receptor activation significantly reduced the placental labyrinth area, expression of some nutrient transporters, and capillary development. Our study indicates that reducing maternal blood GLP-1 levels is a physiological adaptation process that benefits placental development and fetal growth.
Collapse
Affiliation(s)
- Liping Qiao
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States
| | - Cindy Lu
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States
| | - Tianyi Zang
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States
| | - Brianna Dzyuba
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States
| | - Jianhua Shao
- Department of Pediatrics, University of California San Diego, La Jolla, California, United States
| |
Collapse
|
4
|
Paradiž Leitgeb E, Kerčmar J, Križančić Bombek L, Pohorec V, Skelin Klemen M, Slak Rupnik M, Gosak M, Dolenšek J, Stožer A. Exendin-4 affects calcium signalling predominantly during activation and activity of beta cell networks in acute mouse pancreas tissue slices. Front Endocrinol (Lausanne) 2024; 14:1315520. [PMID: 38292770 PMCID: PMC10826511 DOI: 10.3389/fendo.2023.1315520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Tight control of beta cell stimulus-secretion coupling is crucial for maintaining homeostasis of energy-rich nutrients. While glucose serves as a primary regulator of this process, incretins augment beta cell function, partly by enhancing cytosolic [Ca2+] dynamics. However, the details of how precisely they affect beta cell recruitment during activation, their active time, and functional connectivity during plateau activity, and how they influence beta cell deactivation remain to be described. Performing functional multicellular Ca2+ imaging in acute mouse pancreas tissue slices enabled us to systematically assess the effects of the GLP-1 receptor agonist exendin-4 (Ex-4) simultaneously in many coupled beta cells with high resolution. In otherwise substimulatory glucose, Ex-4 was able to recruit approximately a quarter of beta cells into an active state. Costimulation with Ex-4 and stimulatory glucose shortened the activation delays and accelerated beta cell activation dynamics. More specifically, active time increased faster, and the time required to reach half-maximal activation was effectively halved in the presence of Ex-4. Moreover, the active time and regularity of [Ca2+]IC oscillations increased, especially during the first part of beta cell response. In contrast, subsequent addition of Ex-4 to already active cells did not significantly enhance beta cell activity. Network analyses further confirmed increased connectivity during activation and activity in the presence of Ex-4, with hub cell roles remaining rather stable in both control experiments and experiments with Ex-4. Interestingly, Ex-4 demonstrated a biphasic effect on deactivation, slightly prolonging beta cell activity at physiological concentrations and shortening deactivation delays at supraphysiological concentrations. In sum, costimulation by Ex-4 and glucose increases [Ca2+]IC during beta cell activation and activity, indicating that the effect of incretins may, to an important extent, be explained by enhanced [Ca2+]IC signals. During deactivation, previous incretin stimulation does not critically prolong cellular activity, which corroborates their low risk of hypoglycemia.
Collapse
Affiliation(s)
- Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jasmina Kerčmar
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | | | - Vilijem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| |
Collapse
|
5
|
Welch AA, Farahani RA, Egan AM, Laurenti MC, Zeini M, Vella M, Bailey KR, Cobelli C, Dalla Man C, Matveyenko A, Vella A. Glucagon-like peptide-1 receptor blockade impairs islet secretion and glucose metabolism in humans. J Clin Invest 2023; 133:e173495. [PMID: 37751301 PMCID: PMC10645389 DOI: 10.1172/jci173495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUNDProglucagon can be processed to glucagon-like peptide1 (GLP-1) within the islet, but its contribution to islet function in humans remains unknown. We sought to understand whether pancreatic GLP-1 alters islet function in humans and whether this is affected by type 2 diabetes.METHODSWe therefore studied individuals with and without type 2 diabetes on two occasions in random order. On one occasion, exendin 9-39, a competitive antagonist of the GLP-1 Receptor (GLP1R), was infused, while on the other, saline was infused. The tracer dilution technique ([3-3H] glucose) was used to measure glucose turnover during fasting and during a hyperglycemic clamp.RESULTSExendin 9-39 increased fasting glucose concentrations; fasting islet hormone concentrations were unchanged, but inappropriate for the higher fasting glucose observed. In people with type 2 diabetes, fasting glucagon concentrations were markedly elevated and persisted despite hyperglycemia. This impaired suppression of endogenous glucose production by hyperglycemia.CONCLUSIONThese data show that GLP1R blockade impairs islet function, implying that intra-islet GLP1R activation alters islet responses to glucose and does so to a greater degree in people with type 2 diabetes.TRIAL REGISTRATIONThis study was registered at ClinicalTrials.gov NCT04466618.FUNDINGThe study was primarily funded by NIH NIDDK DK126206. AV is supported by DK78646, DK116231 and DK126206. CDM was supported by MIUR (Italian Minister for Education) under the initiative "Departments of Excellence" (Law 232/2016).
Collapse
Affiliation(s)
- Andrew A. Welch
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Rahele A. Farahani
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Aoife M. Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Marcello C. Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Maya Zeini
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Max Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kent R. Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| |
Collapse
|
6
|
Pérez-Arana GM, Díaz-Gómez A, Bancalero-de los Reyes J, Gracia-Romero M, Ribelles-García A, Visiedo F, González-Domínguez Á, Almorza-Gomar D, Prada-Oliveira JA. The role of glucagon after bariatric/metabolic surgery: much more than an "anti-insulin" hormone. Front Endocrinol (Lausanne) 2023; 14:1236103. [PMID: 37635984 PMCID: PMC10451081 DOI: 10.3389/fendo.2023.1236103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/21/2023] [Indexed: 08/29/2023] Open
Abstract
The biological activity of glucagon has recently been proposed to both stimulate hepatic glucose production and also include a paradoxical insulinotropic effect, which could suggest a new role of glucagon in the pathophysiology type 2 diabetes mellitus (T2DM). An insulinotropic role of glucagon has been observed after bariatric/metabolic surgery that is mediated through the GLP-1 receptor on pancreatic beta cells. This effect appears to be modulated by other members of the proglucagon family, playing a key role in the beneficial effects and complications of bariatric/metabolic surgery. Glucagon serves a dual role after sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). In addition to maintaining blood glucose levels, glucagon exhibits an insulinotropic effect, suggesting that glucagon has a more complex function than simply an "anti-insulin hormone".
Collapse
Affiliation(s)
- Gonzalo-Martín Pérez-Arana
- Department of Human Anatomy and Embryology, University of Cadiz, Cádiz, Spain
- Institute for Biomedical Science Research and Innovation (INIBICA), University of Cadiz, Cádiz, Spain
| | | | | | | | | | - Francisco Visiedo
- Department of Human Anatomy and Embryology, University of Cadiz, Cádiz, Spain
- Institute for Biomedical Science Research and Innovation (INIBICA), University of Cadiz, Cádiz, Spain
| | - Álvaro González-Domínguez
- Institute for Biomedical Science Research and Innovation (INIBICA), University of Cadiz, Cádiz, Spain
| | - David Almorza-Gomar
- Institute for Biomedical Science Research and Innovation (INIBICA), University of Cadiz, Cádiz, Spain
- Operative Statistic and Research Department, University of Cádiz, Cádiz, Spain
| | - José-Arturo Prada-Oliveira
- Department of Human Anatomy and Embryology, University of Cadiz, Cádiz, Spain
- Institute for Biomedical Science Research and Innovation (INIBICA), University of Cadiz, Cádiz, Spain
| |
Collapse
|
7
|
Failor M, Bohler M, Cao C, Gilbert E, Cline M. Elucidating the central anorexigenic mechanism of glucagon-like peptide 1 in Japanese quail (Coturnix japonica). Gen Comp Endocrinol 2023; 339:114292. [PMID: 37088166 DOI: 10.1016/j.ygcen.2023.114292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 04/04/2023] [Accepted: 04/19/2023] [Indexed: 04/25/2023]
Abstract
Glucagon-like peptide 1 (GLP-1) elicits a potent reduction in food intake, although the central mechanism mediating this appetite-suppressive effect is not fully understood in all species. To begin to elucidate the molecular mechanisms in quail, we administered GLP-1 via intracerebroventricular (ICV) injection to 7-day-old Japanese quail(Coturnix japonica) and determined effects on food and water intake, behavior, and brain nucleus activation. We observed a reduction in food and water intake, with the lowest effective dose being 0.01 nmol. Quail injected with GLP-1 displayed fewer steps, feeding pecks, exploratory pecks, and jumps, while time spent sitting increased. We quantified c-Fos immunoreactivity at 60 minutes post-injection in hypothalamic and brainstem nuclei that mediate food intake and determined that the hypothalamic paraventricular nucleus (PVN), and nucleus of the solitary tract and area postrema of the brainstem were activated in response to GLP-1.In conclusion, these results suggest that GLP-1 induces anorexigenic effects that are likely mediated at the level of the PVN and brainstem.
Collapse
Affiliation(s)
- Madison Failor
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Mark Bohler
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Chang Cao
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Elizabeth Gilbert
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | - Mark Cline
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.
| |
Collapse
|
8
|
Arble DM, Hutch CR, Hafner H, Stelmak D, Leix K, Sorrell J, Pressler JW, Gregg B, Sandoval DA. The role of preproglucagon peptides in regulating β-cell morphology and responses to streptozotocin-induced diabetes. Am J Physiol Endocrinol Metab 2023; 324:E217-E225. [PMID: 36652401 PMCID: PMC9970646 DOI: 10.1152/ajpendo.00152.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/29/2022] [Accepted: 01/09/2023] [Indexed: 01/19/2023]
Abstract
Insulin secretion from β-cells is tightly regulated by local signaling from preproglucagon (Gcg) products from neighboring α-cells. Physiological paracrine signaling within the microenvironment of the β-cell is altered after metabolic stress, such as high-fat diet or the β-cell toxin, streptozotocin (STZ). Here, we examined the role and source of Gcg peptides in β-cell function and in response to STZ-induced hyperglycemia. We used whole body Gcg null (GcgNull) mice and mice with Gcg expression either specifically within the pancreas (GcgΔPanc) or the intestine (GcgΔIntest). With lower doses of STZ exposure, insulin levels were greater and glucose levels were lower in GcgNull mice compared with wild-type mice. When Gcg was functional only in the intestine, plasma glucagon-like peptide-1 (GLP-1) levels were fully restored but these mice did not have any additional protection from STZ-induced diabetes. Pancreatic Gcg reactivation normalized the hyperglycemic response to STZ. In animals not treated with STZ, GcgNull mice had increased pancreas mass via both α- and β-cell hyperplasia and reactivation of Gcg in the intestine normalized β- but not α-cell mass, whereas pancreatic reactivation normalized both β- and α-cell mass. GcgNull and GcgΔIntest mice maintained higher β-cell mass after treatment with STZ compared with control and GcgΔPanc mice. Although in vivo insulin response to glucose was normal, global lack of Gcg impaired glucose-stimulated insulin secretion in isolated islets. Congenital replacement of Gcg either in the pancreas or intestine normalized glucose-stimulated insulin secretion. Interestingly, mice that had intestinal Gcg reactivated in adulthood had impaired insulin response to KCl. We surmise that the expansion of β-cell mass in the GcgNull mice compensated for decreased individual β-cell insulin secretion, which is sufficient to normalize glucose under physiological conditions and conferred some protection after STZ-induced diabetes.NEW & NOTEWORTHY We examined the role of Gcg on β-cell function under normal and high glucose conditions. GcgNull mice had decreased glucose-stimulated insulin secretion, increased β-cell mass, and partial protection against STZ-induced hyperglycemia. Expression of Gcg within the pancreas normalized these endpoints. Intestinal expression of Gcg only normalized β-cell mass and glucose-stimulated insulin secretion. Increased β-cell mass in GcgNull mice likely compensated for decreased insulin secretion normalizing physiological glucose levels and conferring some protection after STZ-induced diabetes.
Collapse
Affiliation(s)
- Deanna M Arble
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Chelsea R Hutch
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Hannah Hafner
- Department of Pediatrics, Division of Diabetes, Endocrinology and Metabolism, University of Michigan Medicine, Ann Arbor, Michigan, United States
| | - Daria Stelmak
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Kyle Leix
- Department of Surgery, University of Michigan, Ann Arbor, Michigan, United States
| | - Joyce Sorrell
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Joshua W Pressler
- Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, United States
| | - Brigid Gregg
- Department of Pediatrics, Division of Diabetes, Endocrinology and Metabolism, University of Michigan Medicine, Ann Arbor, Michigan, United States
| | - Darleen A Sandoval
- Department of Pediatrics, Section of Nutrition and Division of Endocrinology, Metabolism and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| |
Collapse
|
9
|
Patel R, Parmar N, Rathwa N, Palit SP, Li Y, Garcia-Ocaña A, Begum R. A novel therapeutic combination of sitagliptin and melatonin regenerates pancreatic β-cells in mouse and human islets. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119263. [PMID: 35364117 DOI: 10.1016/j.bbamcr.2022.119263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 03/23/2022] [Accepted: 03/24/2022] [Indexed: 02/06/2023]
Abstract
Autoimmune-led challenge resulting in β-cell loss is responsible for the development of type 1 diabetes (T1D). Melatonin, a pineal hormone or sitagliptin, a dipeptidyl peptidase IV (DPP-IV) inhibitor, has increased β-cell mass in various diabetic models and has immunoregulatory property. Both β-cell regenerative capacity and melatonin secretion decrease with ageing. Thus, we aimed to investigate the therapeutic potential of melatonin combined with sitagliptin on β-cell regeneration under glucotoxic stress, in the streptozotocin-induced young and old diabetic mouse models, and euglycemic humanized islet transplant mouse model. Our results suggest that combination therapy of sitagliptin and melatonin show an additive effect in inducing mouse β-cell regeneration under glucotoxic stress, and in the human islet transplant mouse model. Further, in the young diabetic mouse model, the monotherapies induce β-cell transdifferentiation and reduce β-cell apoptosis whereas, in the old diabetic mouse model, melatonin and sitagliptin induce β-cell proliferation and β-cell transdifferentiation, and it also reduces β-cell apoptosis. Further, in both the models, combination therapy reduces fasting blood glucose levels, increases plasma insulin levels and glucose tolerance and promotes β-cell proliferation, β-cell transdifferentiation, and reduces β-cell apoptosis. It can be concluded that combination therapy is superior to monotherapies in ameliorating diabetic manifestations, and it can be used as a future therapy for β-cell regeneration in diabetes patients.
Collapse
Affiliation(s)
- Roma Patel
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara- 390002, Gujarat, India
| | - Nishant Parmar
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara- 390002, Gujarat, India
| | - Nirali Rathwa
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara- 390002, Gujarat, India
| | - Sayantani Pramanik Palit
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara- 390002, Gujarat, India
| | - Yansui Li
- Diabetes, Obesity and Metabolism Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Adolfo Garcia-Ocaña
- Diabetes, Obesity and Metabolism Institute and Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Rasheedunnisa Begum
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara- 390002, Gujarat, India.
| |
Collapse
|
10
|
Holter MM, Phuong DJ, Lee I, Saikia M, Weikert L, Fountain S, Anderson ET, Fu Q, Zhang S, Sloop KW, Cummings BP. 14-3-3-zeta mediates GLP-1 receptor agonist action to alter α cell proglucagon processing. SCIENCE ADVANCES 2022; 8:eabn3773. [PMID: 35867787 PMCID: PMC9307243 DOI: 10.1126/sciadv.abn3773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Recent studies demonstrate that α cells contribute to glucose-stimulated insulin secretion (GSIS). Glucagon-like peptide-1 receptor (GLP-1R) agonists potently potentiate GSIS, making these drugs useful for diabetes treatment. However, the role of α and β cell paracrine interactions in the effects of GLP-1R agonists is undefined. We previously found that increased β cell GLP-1R signaling activates α cell GLP-1 expression. Here, we characterized the bidirectional paracrine cross-talk by which α and β cells communicate to mediate the effects of the GLP-1R agonist, liraglutide. We find that the effect of liraglutide to enhance GSIS is blunted by α cell ablation in male mice. Furthermore, the effect of β cell GLP-1R signaling to activate α cell GLP-1 is mediated by a secreted protein factor that is regulated by the signaling protein, 14-3-3-zeta, in mouse and human islets. These data refine our understanding of GLP-1 pharmacology and identify 14-3-3-zeta as a potential target to enhance α cell GLP-1 production.
Collapse
Affiliation(s)
- Marlena M. Holter
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Daryl J. Phuong
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Isaac Lee
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Mridusmita Saikia
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Ithaca, NY, USA
| | - Lisa Weikert
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Samantha Fountain
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Elizabeth T. Anderson
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Qin Fu
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Sheng Zhang
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Kyle W. Sloop
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Bethany P. Cummings
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
- Department of Surgery, Center for Alimentary and Metabolic Sciences, School of Medicine, University of California, Davis, Sacramento, CA, USA
| |
Collapse
|
11
|
Shah MA, Haris M, Faheem HI, Hamid A, Yousaf R, Rasul A, Shah GM, Khalil AAK, Wahab A, Khan H, Alhasani RH, Althobaiti NA. Cross-Talk between Obesity and Diabetes: Introducing Polyphenols as an Effective Phytomedicine to Combat the Dual Sword Diabesity. Curr Pharm Des 2022; 28:1523-1542. [PMID: 35762558 DOI: 10.2174/1381612828666220628123224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/06/2022] [Indexed: 12/15/2022]
Abstract
: Obesity-associated diabetes mellitus, a chronic metabolic affliction accounting for 90% of all diabetic patients, has been affecting humanity extremely badly and escalating the risk of developing other serious disorders. It is observed that 0.4 billion people globally have diabetes, whose major cause is obesity. Currently, innumerable synthetic drugs like alogliptin and rosiglitazone are being used to get through diabetes, but they have certain complications, restrictions with severe side effects, and toxicity issues. Recently, the frequency of plant-derived phytochemicals as advantageous substitutes against diabesity is increasing progressively due to their unparalleled benefit of producing less side effects and toxicity. Of these phytochemicals, dietary polyphenols have been accepted as potent agents against the dual sword "diabesity". These polyphenols target certain genes and molecular pathways through dual mechanisms such as adiponectin upregulation, cannabinoid receptor antagonism, free fatty acid oxidation, ghrelin antagonism, glucocorticoid inhibition, sodium-glucose cotransporter inhibition, oxidative stress and inflammation inhibition etc. which sequentially help to combat both diabetes and obesity. In this review, we have summarized the most beneficial natural polyphenols along with their complex molecular pathways during diabesity.
Collapse
Affiliation(s)
| | - Muhammad Haris
- Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Hafiza Ishmal Faheem
- Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Ayesha Hamid
- Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Rimsha Yousaf
- Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Government College University, Faisalabad, Pakistan
| | - Azhar Rasul
- Department of Zoology, Faculty of Life Sciences, Government College University, Faisalabad, Pakistan
| | - Ghulam Mujtaba Shah
- Department of Pharmacy, Hazara University, Mansehra, Pakistan.,Department of Botany, Hazara University, Mansehra, Pakistan
| | - Atif Ali Khan Khalil
- Department of Biological Sciences, National University of Medical Sciences, Rawalpindi 46000, Pakistan
| | - Abdul Wahab
- Department of Pharmacy, Kohat University of Science & Technology, Kohat, Pakistan
| | - Haroon Khan
- Department of Pharmacy, Abdul Wali Khan University, Mardan, Pakistan
| | - Reem Hasaballah Alhasani
- Department of Biology, Faculty of Applied Science, Umm Al-Qura University, 21961 Makkah, Saudi Arabia
| | - Nora A Althobaiti
- Department of Biology, College of Science and Humanities-Al Quwaiiyah, Shaqra University, Al Quwaiiyah, Saudi Arabia
| |
Collapse
|
12
|
Qiao L, Saget S, Lu C, Zang T, Dzyuba B, Hay WW, Shao J. The Essential Role of Pancreatic α-Cells in Maternal Metabolic Adaptation to Pregnancy. Diabetes 2022; 71:978-988. [PMID: 35147704 PMCID: PMC9044124 DOI: 10.2337/db21-0923] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022]
Abstract
Pancreatic α-cells are important in maintaining metabolic homeostasis, but their role in regulating maternal metabolic adaptations to pregnancy has not been studied. The objective of this study was to determine whether pancreatic α-cells respond to pregnancy and their contribution to maternal metabolic adaptation. With use of C57BL/6 mice, the findings of our study showed that pregnancy induced a significant increase of α-cell mass by promoting α-cell proliferation that was associated with a transitory increase of maternal serum glucagon concentration in early pregnancy. Maternal pancreatic GLP-1 content also was significantly increased during pregnancy. Using the inducible Cre/loxp technique, we ablated the α-cells (α-null) before and during pregnancy while maintaining enteroendocrine L-cells and serum GLP-1 in the normal range. In contrast to an improved glucose tolerance test (GTT) before pregnancy, significantly impaired GTT and remarkably higher serum glucose concentrations in the fed state were observed in α-null dams. Glucagon receptor antagonism treatment, however, did not affect measures of maternal glucose metabolism, indicating a dispensable role of glucagon receptor signaling in maternal glucose homeostasis. However, the GLP-1 receptor agonist improved insulin production and glucose metabolism of α-null dams. Furthermore, GLP-1 receptor antagonist Exendin (9-39) attenuated pregnancy-enhanced insulin secretion and GLP-1 restored glucose-induced insulin secretion of cultured islets from α-null dams. Together, these results demonstrate that α-cells play an essential role in controlling maternal metabolic adaptation to pregnancy by enhancing insulin secretion.
Collapse
Affiliation(s)
- Liping Qiao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Sarah Saget
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Cindy Lu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Tianyi Zang
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Brianna Dzyuba
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | | | - Jianhua Shao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
- Corresponding author: Jianhua Shao,
| |
Collapse
|
13
|
Khan D, Moffett RC, Flatt PR, Tarasov AI. Classical and non-classical islet peptides in the control of β-cell function. Peptides 2022; 150:170715. [PMID: 34958851 DOI: 10.1016/j.peptides.2021.170715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/25/2021] [Accepted: 12/17/2021] [Indexed: 12/25/2022]
Abstract
The dual role of the pancreas as both an endocrine and exocrine gland is vital for food digestion and control of nutrient metabolism. The exocrine pancreas secretes enzymes into the small intestine aiding digestion of sugars and fats, whereas the endocrine pancreas secretes a cocktail of hormones into the blood, which is responsible for blood glucose control and regulation of carbohydrate, protein and fat metabolism. Classical islet hormones, insulin, glucagon, pancreatic polypeptide and somatostatin, interact in an autocrine and paracrine manner, to fine-tube the islet function and insulin secretion to the needs of the body. Recently pancreatic islets have been reported to express a number of non-classical peptide hormones involved in metabolic signalling, whose major production site was believed to reside outside pancreas, e.g. in the small intestine. We highlight the key non-classical islet peptides, and consider their involvement, together with established islet hormones, in regulation of stimulus-secretion coupling as well as proliferation, survival and transdifferentiation of β-cells. We furthermore focus on the paracrine interaction between classical and non-classical islet hormones in the maintenance of β-cell function. Understanding the functional relationships between these islet peptides might help to develop novel, more efficient treatments for diabetes and related metabolic disorders.
Collapse
Affiliation(s)
- Dawood Khan
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK.
| | - R Charlotte Moffett
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Peter R Flatt
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| | - Andrei I Tarasov
- Biomedical Sciences Research Institute, School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK
| |
Collapse
|
14
|
Andersen DB, Holst JJ. Peptides in the regulation of glucagon secretion. Peptides 2022; 148:170683. [PMID: 34748791 DOI: 10.1016/j.peptides.2021.170683] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/21/2021] [Accepted: 11/02/2021] [Indexed: 02/06/2023]
Abstract
Glucose homeostasis is maintained by the glucoregulatory hormones, glucagon, insulin and somatostatin, secreted from the islets of Langerhans. Glucagon is the body's most important anti-hypoglycemic hormone, mobilizing glucose from glycogen stores in the liver in response to fasting, thus maintaining plasma glucose levels within healthy limits. Glucagon secretion is regulated by both circulating nutrients, hormones and neuronal inputs. Hormones that may regulate glucagon secretion include locally produced insulin and somatostatin, but also urocortin-3, amylin and pancreatic polypeptide, and from outside the pancreas glucagon-like peptide-1 and 2, peptide tyrosine tyrosine and oxyntomodulin, glucose-dependent insulinotropic polypeptide, neurotensin and ghrelin, as well as the hypothalamic hormones arginine-vasopressin and oxytocin, and calcitonin from the thyroid. Each of these hormones have distinct effects, ranging from regulating blood glucose, to regulating appetite, stomach emptying rate and intestinal motility, which makes them interesting targets for treating metabolic diseases. Awareness regarding the potential effects of the hormones on glucagon secretion is important since secretory abnormalities could manifest as hyperglycemia or even lethal hypoglycemia. Here, we review the effects of each individual hormone on glucagon secretion, their interplay, and how treatments aimed at modulating the plasma levels of these hormones may also influence glucagon secretion and glycemic control.
Collapse
Affiliation(s)
- Daniel B Andersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen N, Denmark; Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
| |
Collapse
|
15
|
Cabrera O, Ficorilli J, Shaw J, Echeverri F, Schwede F, Chepurny OG, Leech CA, Holz GG. Intra-islet glucagon confers β-cell glucose competence for first-phase insulin secretion and favors GLP-1R stimulation by exogenous glucagon. J Biol Chem 2022; 298:101484. [PMID: 34896391 PMCID: PMC8789663 DOI: 10.1016/j.jbc.2021.101484] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 02/07/2023] Open
Abstract
We report that intra-islet glucagon secreted from α-cells signals through β-cell glucagon and GLP-1 receptors (GcgR and GLP-1R), thereby conferring to rat islets their competence to exhibit first-phase glucose-stimulated insulin secretion (GSIS). Thus, in islets not treated with exogenous glucagon or GLP-1, first-phase GSIS is abolished by a GcgR antagonist (LY2786890) or a GLP-1R antagonist (Ex[9-39]). Mechanistically, glucose competence in response to intra-islet glucagon is conditional on β-cell cAMP signaling because it is blocked by the cAMP antagonist prodrug Rp-8-Br-cAMPS-pAB. In its role as a paracrine hormone, intra-islet glucagon binds with high affinity to the GcgR, while also exerting a "spillover" effect to bind with low affinity to the GLP-1R. This produces a right shift of the concentration-response relationship for the potentiation of GSIS by exogenous glucagon. Thus, 0.3 nM glucagon fails to potentiate GSIS, as expected if similar concentrations of intra-islet glucagon already occupy the GcgR. However, 10 to 30 nM glucagon effectively engages the β-cell GLP-1R to potentiate GSIS, an action blocked by Ex[9-39] but not LY2786890. Finally, we report that the action of intra-islet glucagon to support insulin secretion requires a step-wise increase of glucose concentration to trigger first-phase GSIS. It is not measurable when GSIS is stimulated by a gradient of increasing glucose concentrations, as occurs during an oral glucose tolerance test in vivo. Collectively, such findings are understandable if defective intra-islet glucagon action contributes to the characteristic loss of first-phase GSIS in an intravenous glucose tolerance test that is diagnostic of type 2 diabetes in the clinical setting.
Collapse
Affiliation(s)
- Over Cabrera
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA.
| | - James Ficorilli
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Janice Shaw
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | - Frank Schwede
- Biolog Life Science Institute GmbH & Co KG, Bremen, Germany
| | - Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA
| | - Colin A Leech
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA
| | - George G Holz
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA; Department of Pharmacology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA.
| |
Collapse
|
16
|
Oleanolic Acid: Extraction, Characterization and Biological Activity. Nutrients 2022; 14:nu14030623. [PMID: 35276982 PMCID: PMC8838233 DOI: 10.3390/nu14030623] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 11/28/2022] Open
Abstract
Oleanolic acid, a pentacyclic triterpenoid ubiquitously present in the plant kingdom, is receiving outstanding attention from the scientific community due to its biological activity against multiple diseases. Oleanolic acid is endowed with a wide range of biological activities with therapeutic potential by means of complex and multifactorial mechanisms. There is evidence suggesting that oleanolic acid might be effective against dyslipidemia, diabetes and metabolic syndrome, through enhancing insulin response, preserving the functionality and survival of β-cells and protecting against diabetes complications. In addition, several other functions have been proposed, including antiviral, anti-HIV, antibacterial, antifungal, anticarcinogenic, anti-inflammatory, hepatoprotective, gastroprotective, hypolipidemic and anti-atherosclerotic activities, as well as interfering in several stages of the development of different types of cancer; however, due to its hydrophobic nature, oleanolic acid is almost insoluble in water, which has led to a number of approaches to enhance its biopharmaceutical properties. In this scenario, the present review aimed to summarize the current knowledge and the research progress made in the last years on the extraction and characterization of oleanolic acid and its biological activities and the underlying mechanisms of action.
Collapse
|
17
|
Newsholme P, Rowlands J, Rose’Meyer R, Cruzat V. Metabolic Adaptions/Reprogramming in Islet Beta-Cells in Response to Physiological Stimulators—What Are the Consequences. Antioxidants (Basel) 2022; 11:antiox11010108. [PMID: 35052612 PMCID: PMC8773416 DOI: 10.3390/antiox11010108] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/30/2021] [Accepted: 12/31/2021] [Indexed: 12/25/2022] Open
Abstract
Irreversible pancreatic β-cell damage may be a result of chronic exposure to supraphysiological glucose or lipid concentrations or chronic exposure to therapeutic anti-diabetic drugs. The β-cells are able to respond to blood glucose in a narrow concentration range and release insulin in response, following activation of metabolic pathways such as glycolysis and the TCA cycle. The β-cell cannot protect itself from glucose toxicity by blocking glucose uptake, but indeed relies on alternative metabolic protection mechanisms to avoid dysfunction and death. Alteration of normal metabolic pathway function occurs as a counter regulatory response to high nutrient, inflammatory factor, hormone or therapeutic drug concentrations. Metabolic reprogramming is a term widely used to describe a change in regulation of various metabolic enzymes and transporters, usually associated with cell growth and proliferation and may involve reshaping epigenetic responses, in particular the acetylation and methylation of histone proteins and DNA. Other metabolic modifications such as Malonylation, Succinylation, Hydroxybutyrylation, ADP-ribosylation, and Lactylation, may impact regulatory processes, many of which need to be investigated in detail to contribute to current advances in metabolism. By describing multiple mechanisms of metabolic adaption that are available to the β-cell across its lifespan, we hope to identify sites for metabolic reprogramming mechanisms, most of which are incompletely described or understood. Many of these mechanisms are related to prominent antioxidant responses. Here, we have attempted to describe the key β-cell metabolic adaptions and changes which are required for survival and function in various physiological, pathological and pharmacological conditions.
Collapse
Affiliation(s)
- Philip Newsholme
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Jordan Rowlands
- Curtin Medical School and CHIRI, Curtin University, Perth, WA 6845, Australia
- Correspondence: (P.N.); (J.R.)
| | - Roselyn Rose’Meyer
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, QLD 4222, Australia;
| | - Vinicius Cruzat
- Faculty of Health, Torrens University Australia, Brisbane, QLD 4006, Australia;
| |
Collapse
|
18
|
Holter MM, Saikia M, Cummings BP. Alpha-cell paracrine signaling in the regulation of beta-cell insulin secretion. Front Endocrinol (Lausanne) 2022; 13:934775. [PMID: 35957816 PMCID: PMC9360487 DOI: 10.3389/fendo.2022.934775] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/28/2022] [Indexed: 01/14/2023] Open
Abstract
As an incretin hormone, glucagon-like peptide 1 (GLP-1) lowers blood glucose levels by enhancing glucose-stimulated insulin secretion from pancreatic beta-cells. Therapies targeting the GLP-1 receptor (GLP-1R) use the classical incretin model as a physiological framework in which GLP-1 secreted from enteroendocrine L-cells acts on the beta-cell GLP-1R. However, this model has come into question, as evidence demonstrating local, intra-islet GLP-1 production has advanced the competing hypothesis that the incretin activity of GLP-1 may reflect paracrine signaling of GLP-1 from alpha-cells on GLP-1Rs on beta-cells. Additionally, recent studies suggest that alpha-cell-derived glucagon can serve as an additional, albeit less potent, ligand for the beta-cell GLP-1R, thereby expanding the role of alpha-cells beyond that of a counterregulatory cell type. Efforts to understand the role of the alpha-cell in the regulation of islet function have revealed both transcriptional and functional heterogeneity within the alpha-cell population. Further analysis of this heterogeneity suggests that functionally distinct alpha-cell subpopulations display alterations in islet hormone profile. Thus, the role of the alpha-cell in glucose homeostasis has evolved in recent years, such that alpha-cell to beta-cell communication now presents a critical axis regulating the functional capacity of beta-cells. Herein, we describe and integrate recent advances in our understanding of the impact of alpha-cell paracrine signaling on insulin secretory dynamics and how this intra-islet crosstalk more broadly contributes to whole-body glucose regulation in health and under metabolic stress. Moreover, we explore how these conceptual changes in our understanding of intra-islet GLP-1 biology may impact our understanding of the mechanisms of incretin-based therapeutics.
Collapse
Affiliation(s)
- Marlena M. Holter
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- *Correspondence: Marlena M. Holter,
| | - Mridusmita Saikia
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Bethany P. Cummings
- School of Medicine, Department of Surgery, Center for Alimentary and Metabolic Sciences, University of California, Davis, Sacramento, CA, United States
| |
Collapse
|
19
|
Guo X, Cui C, Song J, He Q, Zang N, Hu H, Wang X, Li D, Wang C, Hou X, Li X, Liang K, Yan F, Chen L. Mof acetyltransferase inhibition ameliorates glucose intolerance and islet dysfunction of type 2 diabetes via targeting pancreatic α-cells. Mol Cell Endocrinol 2021; 537:111425. [PMID: 34391847 DOI: 10.1016/j.mce.2021.111425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 01/04/2023]
Abstract
BACKGROUND Previously, we reported that Mof was highly expressed in α-cells, and its knockdown led to ameliorated fasting blood glucose (FBG) and glucose tolerance in non-diabetic mice, attributed by reduced total α-cell but enhanced prohormone convertase (PC)1/3-positive α-cell mass. However, how Mof and histone 4 lysine 16 acetylation (H4K16ac) control α-cell and whether Mof inhibition improves glucose handling in type 2 diabetes (T2DM) mice remain unknown. METHODS Mof overexpression and chromatin immunoprecipitation sequence (ChIP-seq) based on H4K16ac were applied to determine the effect of Mof on α-cell transcriptional factors and underlying mechanism. Then we administrated mg149 to α-TC1-6 cell line, wild type, db/db and diet-induced obesity (DIO) mice to observe the impact of Mof inhibition in vitro and in vivo. In vitro, western blotting and TUNEL staining were used to examine α-cell apoptosis and function. In vivo, glucose tolerance, hormone levels, islet population, α-cell ratio and the co-staining of glucagon and PC1/3 or PC2 were examined. RESULTS Mof activated α-cell-specific transcriptional network. ChIP-seq results indicated that H4K16ac targeted essential genes regulating α-cell differentiation and function. Mof activity inhibition in vitro caused impaired α-cell function and enhanced apoptosis. In vivo, it contributed to ameliorated glucose intolerance and islet dysfunction, characterized by decreased fasting glucagon and elevated post-challenge insulin levels in T2DM mice. CONCLUSION Mof regulates α-cell differentiation and function via acetylating H4K16ac and H4K16ac binding to Pax6 and Foxa2 promoters. Mof inhibition may be a potential interventional target for T2DM, which led to decreased α-cell ratio but increased PC1/3-positive α-cells.
Collapse
Affiliation(s)
- Xinghong Guo
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Chen Cui
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Jia Song
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Qin He
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Nan Zang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Huiqing Hu
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xiaojie Wang
- Department of Pharmacology, Basic Medicine School of Shandong University, Jinan, 250012, Shandong, China
| | - Danyang Li
- Department of Rehabilitation, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Chuan Wang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xiangzhi Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Life Science School of Shandong University, Qingdao, 266237, Shandong, China
| | - Kai Liang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China
| | - Fei Yan
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
| | - Li Chen
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
| |
Collapse
|
20
|
Asadi F, Dhanvantari S. Pathways of Glucagon Secretion and Trafficking in the Pancreatic Alpha Cell: Novel Pathways, Proteins, and Targets for Hyperglucagonemia. Front Endocrinol (Lausanne) 2021; 12:726368. [PMID: 34659118 PMCID: PMC8511682 DOI: 10.3389/fendo.2021.726368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/13/2021] [Indexed: 12/15/2022] Open
Abstract
Patients with diabetes mellitus exhibit hyperglucagonemia, or excess glucagon secretion, which may be the underlying cause of the hyperglycemia of diabetes. Defective alpha cell secretory responses to glucose and paracrine effectors in both Type 1 and Type 2 diabetes may drive the development of hyperglucagonemia. Therefore, uncovering the mechanisms that regulate glucagon secretion from the pancreatic alpha cell is critical for developing improved treatments for diabetes. In this review, we focus on aspects of alpha cell biology for possible mechanisms for alpha cell dysfunction in diabetes: proglucagon processing, intrinsic and paracrine control of glucagon secretion, secretory granule dynamics, and alterations in intracellular trafficking. We explore possible clues gleaned from these studies in how inhibition of glucagon secretion can be targeted as a treatment for diabetes mellitus.
Collapse
Affiliation(s)
- Farzad Asadi
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
- Program in Metabolism and Diabetes, Lawson Health Research Institute, London, ON, Canada
| | - Savita Dhanvantari
- Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
- Program in Metabolism and Diabetes, Lawson Health Research Institute, London, ON, Canada
- Imaging Research Program, Lawson Health Research Institute, London, ON, Canada
- Department of Medical Biophysics, Western University, London, ON, Canada
| |
Collapse
|
21
|
Zhang Y, Han C, Zhu W, Yang G, Peng X, Mehta S, Zhang J, Chen L, Liu Y. Glucagon Potentiates Insulin Secretion Via β-Cell GCGR at Physiological Concentrations of Glucose. Cells 2021; 10:cells10092495. [PMID: 34572144 PMCID: PMC8471175 DOI: 10.3390/cells10092495] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/21/2022] Open
Abstract
Incretin-potentiated glucose-stimulated insulin secretion (GSIS) is critical to maintaining euglycemia, of which GLP-1 receptor (GLP-1R) on β-cells plays an indispensable role. Recently, α-cell-derived glucagon but not intestine-derived GLP-1 has been proposed as the critical hormone that potentiates GSIS via GLP-1R. However, the function of glucagon receptors (GCGR) on β-cells remains elusive. Here, using GCGR or GLP-1R antagonists, in combination with glucagon, to treat single β-cells, α-β cell clusters and isolated islets, we found that glucagon potentiates insulin secretion via β-cell GCGR at physiological but not high concentrations of glucose. Furthermore, we transfected primary mouse β-cells with RAB-ICUE (a genetically encoded cAMP fluorescence indicator) to monitor cAMP level after glucose stimulation and GCGR activation. Using specific inhibitors of different adenylyl cyclase (AC) family members, we revealed that high glucose concentration or GCGR activation independently evoked cAMP elevation via AC5 in β-cells, thus high glucose stimulation bypassed GCGR in promoting insulin secretion. Additionally, we generated β-cell-specific GCGR knockout mice which glucose intolerance was more severe when fed a high-fat diet (HFD). We further found that β-cell GCGR activation promoted GSIS more than GLP-1R in HFD, indicating the critical role of GCGR in maintaining glucose homeostasis during nutrient overload.
Collapse
Affiliation(s)
- Yulin Zhang
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Chengsheng Han
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Wenzhen Zhu
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Guoyi Yang
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Xiaohong Peng
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Sohum Mehta
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0702, USA; (S.M.); (J.Z.)
| | - Jin Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0702, USA; (S.M.); (J.Z.)
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
- PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
- Beijing Academy of Artificial Intelligence, Beijing 100871, China
- Correspondence: (L.C.); (Y.L.)
| | - Yanmei Liu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou 510631, China
- Correspondence: (L.C.); (Y.L.)
| |
Collapse
|
22
|
Kumar S, Mittal A, Mittal A. A review upon medicinal perspective and designing rationale of DPP-4 inhibitors. Bioorg Med Chem 2021; 46:116354. [PMID: 34428715 DOI: 10.1016/j.bmc.2021.116354] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 12/13/2022]
Abstract
Type 2 Diabetes Mellitus (T2DM) is one of the highly prevalence disorder and increasing day by day worldwidely. T2DM is a metabolic disorder, which is characterized by deficiency in insulin or resistance to insulin and thus increases the glucose levels in the blood. Various approaches are there to treat diabetes but still there is no cure for this disease. DPP-4 inhibitor is a privileged target in the field of drug discovery and provides various opportunities in exploring this target for development of molecules as antidiabetic agents. DPP-4 acts by inhibiting the incretin action and thus decreases the level of blood glucose by imparting minimal side effects. Sitagliptin, vildagliptin, linagliptin etc. are the different DPP-4 based drugs approved throughout the world for the treatment of diabetes mellitus. Cyanopyrrolidines, triazolopiperazine amide, pyrrolidines are basic core nucleus present in various DPP-4 inhibitors and has potential effects. In the past few years, researchers had applied various approaches to synthesize potent DPP-4 inhibitors as antidiabetic agent without side effects like weight gain, cardiovascular risks, retinopathy etc. This review will also emphasize the recent strategies and rationale utilized by researchers for the development of DPP-4 inhibitors. This review also reveals about the various other approaches like molecular modelling, ligand based drug designing, high throughput screening etc. are used by the various research group for the development of potential DPP-4 inhibitors.
Collapse
Affiliation(s)
- Shubham Kumar
- Faculty of Pharmaceutical Sciences, PCTE Group of Institutes, Campus-2, Near Baddowal Cantt. Ferozepur Road, Ludhiana 142021, India; Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Jalandhar-Delhi G.T. Road (NH-1), Phagwara, Punjab 144411, India
| | - Anu Mittal
- Department of Chemistry, Guru Nanak Dev University College, Patti, Distt. Tarn Taran, India
| | - Amit Mittal
- Department of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Lovely Professional University, Jalandhar-Delhi G.T. Road (NH-1), Phagwara, Punjab 144411, India.
| |
Collapse
|
23
|
Galvin SG, Kay RG, Foreman R, Larraufie P, Meek CL, Biggs E, Ravn P, Jermutus L, Reimann F, Gribble FM. The Human and Mouse Islet Peptidome: Effects of Obesity and Type 2 Diabetes, and Assessment of Intraislet Production of Glucagon-like Peptide-1. J Proteome Res 2021; 20:4507-4517. [PMID: 34423991 PMCID: PMC8419866 DOI: 10.1021/acs.jproteome.1c00463] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Indexed: 02/07/2023]
Abstract
To characterize the impact of metabolic disease on the peptidome of human and mouse pancreatic islets, LC-MS was used to analyze extracts of human and mouse islets, purified mouse alpha, beta, and delta cells, supernatants from mouse islet incubations, and plasma from patients with type 2 diabetes. Islets were obtained from healthy and type 2 diabetic human donors, and mice on chow or high fat diet. All major islet hormones were detected in lysed islets as well as numerous peptides from vesicular proteins including granins and processing enzymes. Glucose-dependent insulinotropic peptide (GIP) was not detectable. High fat diet modestly increased islet content of proinsulin-derived peptides in mice. Human diabetic islets contained increased content of proglucagon-derived peptides at the expense of insulin, but no evident prohormone processing defects. Diabetic plasma, however, contained increased ratios of proinsulin and des-31,32-proinsulin to insulin. Active GLP-1 was detectable in human and mouse islets but 100-1000-fold less abundant than glucagon. LC-MS offers advantages over antibody-based approaches for identifying exact peptide sequences, and revealed a shift toward islet insulin production in high fat fed mice, and toward proglucagon production in type 2 diabetes, with no evidence of systematic defective prohormone processing.
Collapse
Affiliation(s)
- Sam G. Galvin
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Richard G. Kay
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Rachel Foreman
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Pierre Larraufie
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Claire L. Meek
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Emma Biggs
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Peter Ravn
- Research
and Early Development Cardiovascular, Renal and Metabolism (CVRM),
BioPharmaceuticals R&D, AstraZeneca
Ltd., Cambridge, CB21 6GH, U.K.
| | - Lutz Jermutus
- Research
and Early Development Cardiovascular, Renal and Metabolism (CVRM),
BioPharmaceuticals R&D, AstraZeneca
Ltd., Cambridge, CB21 6GH, U.K.
| | - Frank Reimann
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Fiona M. Gribble
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| |
Collapse
|
24
|
Ramzy A, Kieffer TJ. Altered islet prohormone processing: A cause or consequence of diabetes? Physiol Rev 2021; 102:155-208. [PMID: 34280055 DOI: 10.1152/physrev.00008.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peptide hormones are first produced as larger precursor prohormones that require endoproteolytic cleavage to liberate the mature hormones. A structurally conserved but functionally distinct family of nine prohormone convertase enzymes (PCs) are responsible for cleavage of protein precursors of which PC1/3 and PC2 are known to be exclusive to neuroendocrine cells and responsible for prohormone cleavage. Differential expression of PCs within tissues define prohormone processing; whereas glucagon is the major product liberated from proglucagon via PC2 in pancreatic α-cells, proglucagon is preferentially processed by PC1/3 in intestinal L cells to produce glucagon-like peptides 1 and 2 (GLP-1, GLP-2). Beyond our understanding of processing of islet prohormones in healthy islets, there is convincing evidence that proinsulin, proIAPP, and proglucagon processing is altered during prediabetes and diabetes. There is predictive value of elevated circulating proinsulin or proinsulin : C-peptide ratio for progression to type 2 diabetes and elevated proinsulin or proinsulin : C-peptide is predictive for development of type 1 diabetes in at risk groups. After onset of diabetes, patients have elevated circulating proinsulin and proIAPP and proinsulin may be an autoantigen in type 1 diabetes. Further, preclinical studies reveal that α-cells have altered proglucagon processing during diabetes leading to increased GLP-1 production. We conclude that despite strong associative data, current evidence is inconclusive on the potential causal role of impaired prohormone processing in diabetes, and suggest that future work should focus on resolving the question of whether altered prohormone processing is a causal driver or merely a consequence of diabetes pathology.
Collapse
Affiliation(s)
- Adam Ramzy
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Timothy J Kieffer
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
25
|
Zeigerer A, Sekar R, Kleinert M, Nason S, Habegger KM, Müller TD. Glucagon's Metabolic Action in Health and Disease. Compr Physiol 2021; 11:1759-1783. [PMID: 33792899 PMCID: PMC8513137 DOI: 10.1002/cphy.c200013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Discovered almost simultaneously with insulin, glucagon is a pleiotropic hormone with metabolic action that goes far beyond its classical role to increase blood glucose. Albeit best known for its ability to directly act on the liver to increase de novo glucose production and to inhibit glycogen breakdown, glucagon lowers body weight by decreasing food intake and by increasing metabolic rate. Glucagon further promotes lipolysis and lipid oxidation and has positive chronotropic and inotropic effects in the heart. Interestingly, recent decades have witnessed a remarkable renaissance of glucagon's biology with the acknowledgment that glucagon has pharmacological value beyond its classical use as rescue medication to treat severe hypoglycemia. In this article, we summarize the multifaceted nature of glucagon with a special focus on its hepatic action and discuss the pharmacological potential of either agonizing or antagonizing the glucagon receptor for health and disease. © 2021 American Physiological Society. Compr Physiol 11:1759-1783, 2021.
Collapse
Affiliation(s)
- Anja Zeigerer
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Revathi Sekar
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Maximilian Kleinert
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Shelly Nason
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kirk M. Habegger
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Timo D. Müller
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
| |
Collapse
|
26
|
Abstract
Glucagon-Like Peptide-1 (GLP-1) is an important peptide hormone secreted by L-cells in the gastrointestinal tract in response to nutrients. It is produced by the differential cleavage of the proglucagon peptide. GLP-1 elicits a wide variety of physiological responses in many tissues that contribute to metabolic homeostasis. For these reasons, therapies designed to either increase endogenous GLP-1 levels or introduce exogenous peptide mimetics are now widely used in the management of diabetes. In addition to GLP-1 production from L-cells, recent reports suggest that pancreatic islet alpha cells may also synthesize and secrete GLP-1. Intra-islet GLP-1 may therefore play an unappreciated role in islet health and glucose regulation, suggesting a potential functional paracrine role for islet-derived GLP-1. In this review, we assess the current literature from an islet-centric point-of-view to better understand the production, degradation, and actions of GLP-1 within the endocrine pancreas in rodents and humans. The relevance of intra-islet GLP-1 in human physiology is discussed regarding the potential role of intra-islet GLP-1 in islet health and dysfunction.
Collapse
Affiliation(s)
- Scott A. Campbell
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montreal Diabetes Research Centre CRCHUM, Montréal, Canada
| | - Janyne Johnson
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Peter E. Light
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- CONTACT Peter E. Light Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AlbertaT6G 2E1, Canada
| |
Collapse
|
27
|
Saikia M, Holter MM, Donahue LR, Lee IS, Zheng QC, Wise JL, Todero JE, Phuong DJ, Garibay D, Coch R, Sloop KW, Garcia-Ocana A, Danko CG, Cummings BP. GLP-1 receptor signaling increases PCSK1 and β cell features in human α cells. JCI Insight 2021; 6:141851. [PMID: 33554958 PMCID: PMC7934853 DOI: 10.1172/jci.insight.141851] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/29/2020] [Indexed: 02/06/2023] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that potentiates glucose-stimulated insulin secretion. GLP-1 is classically produced by gut L cells; however, under certain circumstances α cells can express the prohormone convertase required for proglucagon processing to GLP-1, prohormone convertase 1/3 (PC1/3), and can produce GLP-1. However, the mechanisms through which this occurs are poorly defined. Understanding the mechanisms by which α cell PC1/3 expression can be activated may reveal new targets for diabetes treatment. Here, we demonstrate that the GLP-1 receptor (GLP-1R) agonist, liraglutide, increased α cell GLP-1 expression in a β cell GLP-1R-dependent manner. We demonstrate that this effect of liraglutide was translationally relevant in human islets through application of a new scRNA-seq technology, DART-Seq. We found that the effect of liraglutide to increase α cell PC1/3 mRNA expression occurred in a subcluster of α cells and was associated with increased expression of other β cell-like genes, which we confirmed by IHC. Finally, we found that the effect of liraglutide to increase bihormonal insulin+ glucagon+ cells was mediated by the β cell GLP-1R in mice. Together, our data validate a high-sensitivity method for scRNA-seq in human islets and identify a potentially novel GLP-1-mediated pathway regulating human α cell function.
Collapse
Affiliation(s)
- Mridusmita Saikia
- Department of Biomedical Sciences and
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, New York, USA
| | | | | | | | | | | | | | | | | | - Reilly Coch
- Cayuga Medical Center, Ithaca, New York, USA
| | - Kyle W Sloop
- Diabetes and Complications, Lilly Research Laboratories, Lilly, Indianapolis, Indiana, USA
| | | | - Charles G Danko
- Department of Biomedical Sciences and
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, New York, USA
| | | |
Collapse
|
28
|
Ribeiro-Parenti L, Jarry AC, Cavin JB, Willemetz A, Le Beyec J, Sannier A, Benadda S, Pelletier AL, Hourseau M, Léger T, Morlet B, Couvelard A, Anini Y, Msika S, Marmuse JP, Ledoux S, Le Gall M, Bado A. Bariatric surgery induces a new gastric mucosa phenotype with increased functional glucagon-like peptide-1 expressing cells. Nat Commun 2021; 12:110. [PMID: 33397977 PMCID: PMC7782689 DOI: 10.1038/s41467-020-20301-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/19/2020] [Indexed: 12/19/2022] Open
Abstract
Glucagon-Like Peptide-1 (GLP-1) undergoes rapid inactivation by dipeptidyl peptidase-4 (DPP4) suggesting that target receptors may be activated by locally produced GLP-1. Here we describe GLP-1 positive cells in the rat and human stomach and found these cells co-expressing ghrelin or somatostatin and able to secrete active GLP-1 in the rats. In lean rats, a gastric load of glucose induces a rapid and parallel rise in GLP-1 levels in both the gastric and the portal veins. This rise in portal GLP-1 levels was abrogated in HFD obese rats but restored after vertical sleeve gastrectomy (VSG) surgery. Finally, obese rats and individuals operated on Roux-en-Y gastric bypass and SG display a new gastric mucosa phenotype with hyperplasia of the mucus neck cells concomitant with increased density of GLP-1 positive cells. This report brings to light the contribution of gastric GLP-1 expressing cells that undergo plasticity changes after bariatric surgeries, to circulating GLP-1 levels.
Collapse
Affiliation(s)
- Lara Ribeiro-Parenti
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Service de Chirurgie Générale Œsogastrique et Bariatrique, Hôpital Bichat - Claude-Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Anne-Charlotte Jarry
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
| | - Jean-Baptiste Cavin
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
| | - Alexandra Willemetz
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
| | - Johanne Le Beyec
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Sorbonne Université, AP-HP, Hôpital Pitié-Salpêtrière-Charles Foix, Biochimie Endocrinienne et Oncologique, Paris, France
| | - Aurélie Sannier
- Department of Pathology Bichat Hospital, AP-HP, 75018, Paris, France
| | - Samira Benadda
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Cell and Tissue Imaging Platform, Inserm, U1149, CNRS, ERL8252, 75018, Paris, France
| | - Anne-Laure Pelletier
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
| | - Muriel Hourseau
- Department of Pathology Bichat Hospital, AP-HP, 75018, Paris, France
| | - Thibaut Léger
- Université de Paris, Mass Spectrometry Laboratory, Institut Jacques Monod, UMR 7592, CNRS, 75205, Paris, France
- Université Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail) - UMR_S 1085, 35000, Rennes, France
| | - Bastien Morlet
- Université de Paris, Mass Spectrometry Laboratory, Institut Jacques Monod, UMR 7592, CNRS, 75205, Paris, France
| | - Anne Couvelard
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Department of Pathology Bichat Hospital, AP-HP, 75018, Paris, France
| | - Younes Anini
- Department of Obstetrics and Gynecology, Dalhousie University, IWK Health Centre, Halifax, New Brunswick, Canada
| | - Simon Msika
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Service de Chirurgie Générale Œsogastrique et Bariatrique, Hôpital Bichat - Claude-Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Jean-Pierre Marmuse
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Service de Chirurgie Générale Œsogastrique et Bariatrique, Hôpital Bichat - Claude-Bernard, Assistance Publique-Hôpitaux de Paris, Paris, France
| | - Sévérine Ledoux
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France
- Service des Explorations Fonctionnelles Hôpital Louis Mourier, AP-HP, Centre Intégré Nord Francilien de prise en charge de l'Obésité (CINFO), 92701, Colombes, France
| | - Maude Le Gall
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France.
| | - André Bado
- Université de Paris, Inserm U1149, Centre de Recherche sur l'inflammation, Paris, France.
| |
Collapse
|
29
|
He W, Rebello OD, Henne A, Nikolka F, Klein T, Maedler K. GLP-2 Is Locally Produced From Human Islets and Balances Inflammation Through an Inter-Islet-Immune Cell Crosstalk. Front Endocrinol (Lausanne) 2021; 12:697120. [PMID: 34290670 PMCID: PMC8287580 DOI: 10.3389/fendo.2021.697120] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 06/18/2021] [Indexed: 12/12/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) shows robust protective effects on β-cell survival and function and GLP-1 based therapies are successfully applied for type-2 diabetes (T2D) and obesity. Another cleavage product of pro-glucagon, Glucagon-like peptide-2 (GLP-2; both GLP-1 and GLP-2 are inactivated by DPP-4) has received little attention in its action inside pancreatic islets. In this study, we investigated GLP-2 production, GLP-2 receptor (GLP-2R) expression and the effect of GLP-2R activation in human islets. Isolated human islets from non-diabetic donors were exposed to diabetogenic conditions: high glucose, palmitate, cytokine mix (IL-1β/IFN-γ) or Lipopolysaccharide (LPS) in the presence or absence of the DPP4-inhibitor linagliptin, the TLR4 inhibitor TAK-242, the GLP-2R agonist teduglutide and/or its antagonist GLP-2(3-33). Human islets under control conditions secreted active GLP-2 (full-length, non-cleaved by DPP4) into the culture media, which was increased by combined high glucose/palmitate, the cytokine mix and LPS and highly potentiated by linagliptin. Low but reproducible GLP-2R mRNA expression was found in all analyzed human islet isolations from 10 donors, which was reduced by pro-inflammatory stimuli: the cytokine mix and LPS. GLP-2R activation by teduglutide neither affected acute or glucose stimulated insulin secretion nor insulin content. Also, teduglutide had no effect on high glucose/palmitate- or LPS-induced dysfunction in cultured human islets but dampened LPS-induced macrophage-dependent IL1B and IL10 expression, while its antagonist GLP-2(3-33) abolished such reduction. In contrast, the expression of islet macrophage-independent cytokines IL6, IL8 and TNF was not affected by teduglutide. Medium conditioned by teduglutide-exposed human islets attenuated M1-like polarization of human monocyte-derived macrophages, evidenced by a lower mRNA expression of pro-inflammatory cytokines, compared to vehicle treated islets, and a reduced production of itaconate and succinate, marker metabolites of pro-inflammatory macrophages. Our results reveal intra-islet production of GLP-2 and GLP-2R expression in human islets. Despite no impact on β-cell function, local GLP-2R activation reduced islet inflammation which might be mediated by a crosstalk between endocrine cells and macrophages.
Collapse
Affiliation(s)
- Wei He
- Centre for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
- *Correspondence: Wei He, ; Kathrin Maedler,
| | - Osmond D. Rebello
- Centre for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
| | - Antonia Henne
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
- Faculty of Chemistry and Pharmacy, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | - Fabian Nikolka
- Department of Bioinformatics and Biochemistry and Braunschweig Integrated Center of Systems Biology (BRICS), Technische Universität Braunschweig, Braunschweig, Germany
| | - Thomas Klein
- CardioMetabolic Diseases Research, Boehringer Ingelheim GmbH & Co. KG, Biberach, Germany
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, Bremen, Germany
- *Correspondence: Wei He, ; Kathrin Maedler,
| |
Collapse
|
30
|
Galsgaard KD. The Vicious Circle of Hepatic Glucagon Resistance in Non-Alcoholic Fatty Liver Disease. J Clin Med 2020; 9:jcm9124049. [PMID: 33333850 PMCID: PMC7765287 DOI: 10.3390/jcm9124049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 02/08/2023] Open
Abstract
A key criterion for the most common chronic liver disease—non-alcoholic fatty liver disease (NAFLD)—is an intrahepatic fat content above 5% in individuals who are not using steatogenic agents or having significant alcohol intake. Subjects with NAFLD have increased plasma concentrations of glucagon, and emerging evidence indicates that subjects with NAFLD may show hepatic glucagon resistance. For many years, glucagon has been thought of as the counterregulatory hormone to insulin with a primary function of increasing blood glucose concentrations and protecting against hypoglycemia. However, in recent years, glucagon has re-emerged as an important regulator of other metabolic processes including lipid and amino acid/protein metabolism. This review discusses the evidence that in NAFLD, hepatic glucagon resistance may result in a dysregulated lipid and amino acid/protein metabolism, leading to excess accumulation of fat, hyperglucagonemia, and increased oxidative stress contributing to the worsening/progression of NAFLD.
Collapse
Affiliation(s)
- Katrine D. Galsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; ; Tel.: +45-6044-6145
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| |
Collapse
|
31
|
Sarnobat D, Moffett CR, Tanday N, Reimann F, Gribble FM, Flatt PR, Tarasov AI. Antidiabetic drug therapy alleviates type 1 diabetes in mice by promoting pancreatic α-cell transdifferentiation. Biochem Pharmacol 2020; 182:114216. [PMID: 32926875 PMCID: PMC7614179 DOI: 10.1016/j.bcp.2020.114216] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/03/2020] [Accepted: 09/04/2020] [Indexed: 12/17/2022]
Abstract
Gut incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), enhance secretion of insulin in a glucose-dependent manner, predominantly by elevating cytosolic levels of cAMP in pancreatic β-cells. Successful targeting of the incretin pathway by several drugs, however, suggests the antidiabetic mechanism is likely to span beyond the acute effect on hormone secretion and include, for instance, stimulation of β-cell growth and/or proliferation. Likewise, the antidiabetic action of kidney sodium-glucose linked transporter-2 (SGLT-2) inhibitors exceeds simple increase glucose excretion. Potential reasons for these 'added benefits' may lie in the long-term effects of these signals on developmental aspects of pancreatic islet cells. In this work, we explored if the incretin mimetics or SGLT-2 inhibitors can affect the size of the islet α- or β-cell compartments, under the condition of β-cell stress. To that end, we utilised mice expressing YFP specifically in pancreatic α-cells, in which we modelled type 1 diabetes by injecting streptozotocin, followed by a 10-day administration of liraglutide, sitagliptin or dapagliflozin. We observed an onset of diabetic phenotype, which was partially reversed by the administration of the antidiabetic drugs. The mechanism for the reversal included induction of β-cell proliferation, decrease in β-cell apoptosis and, for the incretin mimetics, transdifferentiation of α-cells into β-cells. Our data therefore emphasize the role of chronic incretin signalling in induction of α-/β-cell transdifferentiation. We conclude that incretin peptides may act directly on islet cells, making use of the endogenous local sites of 'ectopic' expression, whereas SGLT-2 inhibitors work via protecting β-cells from chronic hyperglycaemia.
Collapse
Affiliation(s)
- Dipak Sarnobat
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, UK
| | - Charlotte R Moffett
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, UK
| | - Neil Tanday
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, UK
| | - Frank Reimann
- Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, UK
| | - Fiona M Gribble
- Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, UK
| | - Peter R Flatt
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, UK
| | - Andrei I Tarasov
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine BT52 1SA, UK.
| |
Collapse
|
32
|
Castellano JM, Espinosa JM, Perona JS. Modulation of Lipid Transport and Adipose Tissue Deposition by Small Lipophilic Compounds. Front Cell Dev Biol 2020; 8:555359. [PMID: 33163484 PMCID: PMC7591460 DOI: 10.3389/fcell.2020.555359] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/01/2020] [Indexed: 12/14/2022] Open
Abstract
Small lipophilic molecules present in foods of plant origin have relevant biological activities at rather low concentrations. Evidence suggests that phytosterols, carotenoids, terpenoids, and tocopherols can interact with different metabolic pathways, exerting beneficial effects against a number of metabolic diseases. These small molecules can modulate triacylglycerol absorption in the intestine and the biosynthesis of chylomicrons, the lipid carriers in the blood. Once in the bloodstream, they can impact lipoprotein clearance from blood, thereby affecting fatty acid release, incorporation into adipocytes and triglyceride reassembling and deposit. Consequently, some of these molecules can regulate pathophysiological processes associated to obesity and its related conditions, such as insulin resistance, metabolic syndrome and type-2 diabetes. The protective capacity of some lipophilic small molecules on oxidative and chemotoxic stress, can modify the expression of key genes in the adaptive cellular response, such as transcription factors, contributing to prevent the inflammatory status of adipose tissue. These small lipophilic compounds can be incorporated into diet as natural parts of food but they can also be employed to supplement other dietary and pharmacologic products as nutraceuticals, exerting protective effects against the development of metabolic diseases in which inflammation is involved. The aim of this review is to summarize the current knowledge of the influence of dietary lipophilic small biomolecules (phytosterols, carotenoids, tocopherols, and triterpenes) on lipid transport, as well as on the effects they may have on pathophysiological metabolic states, related to obesity, insulin resistance and inflammation, providing an evidence-based summary of their main beneficial effects on human health.
Collapse
Affiliation(s)
- José M Castellano
- Group of Bioactive Compounds, Nutrition and Health, Department of Food and Health, Instituto de la Grasa-Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Juan M Espinosa
- Group of Bioactive Compounds, Nutrition and Health, Department of Food and Health, Instituto de la Grasa-Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Javier S Perona
- Group of Bioactive Compounds, Nutrition and Health, Department of Food and Health, Instituto de la Grasa-Consejo Superior de Investigaciones Científicas, Seville, Spain
| |
Collapse
|
33
|
Guo X, Li D, Song J, Yang Q, Wang M, Yang Y, Wang L, Hou X, Chen L, Li X. Mof regulates glucose level via altering different α-cell subset mass and intra-islet glucagon-like peptide-1, glucagon secretion. Metabolism 2020; 109:154290. [PMID: 32522488 DOI: 10.1016/j.metabol.2020.154290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Males absent on the first (Mof) is implicated in gene control of diverse biological processes, such as cell growth, differentiation, apoptosis and autophagy. However, the relationship between glucose regulation and Mof-mediated transcription events remains unexplored. We aimed to unravel the role of Mof in glucose regulation by using global and pancreatic α-cell-specific Mof-deficient mice in vivo and α-TC1-6 cell line in vitro. METHODS We used tamoxifen-induced temporal Mof-deficient mice first to show Mof regulate glucose homeostasis, islet cell proportions and hormone secretion. Then we used α-cell-specific Mof-deficient mice to clarify how α-cell subsets and β-cell mass were regulated and corresponding hormone level alterations. Ultimately, we used small interfering RNA (siRNA) to knockdown Mof in α-TC1-6 and unravel the mechanism regulating α-cell mass and glucagon secretion. RESULTS Mof was mainly expressed in α-cells. Global Mof deficiency led to lower glucose levels, attributed by decreased α/β-cell ratio and glucagon secretion. α-cell-specific Mof-deficient mice exhibited similar alterations, with more reduced prohormone convertase 2 (PC2)-positive α-cell mass, responsible for less glucagon, and enhanced prohormone convertase 1 (PC1/3)-positive α-cell mass, leading to more glucagon-like peptide-1 (GLP-1) secretion, thus increased β-cell mass and insulin secretion. In vitro, increased DNA damage, dysregulated autophagy, enhanced apoptosis and altered cell fate factors expressions upon Mof knockdown were observed. Genes and pathways linked to impaired glucagon secretion were uncovered through transcriptome sequencing. CONCLUSION Mof is a potential interventional target for glucose regulation, from the aspects of both α-cell subset mass and glucagon, intra-islet GLP-1 secretion. Upon Mof deficiency, Up-regulated PC1/3 but down-regulated PC2-positive α-cell mass, leads to more GLP-1 and insulin but less glucagon secretion, and contributed to lower glucose level.
Collapse
Affiliation(s)
- Xinghong Guo
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China; Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Danyang Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China; Department of Rehabilitation, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Jia Song
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Qibing Yang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Meng Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Yang Yang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Lingshu Wang
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, Shandong, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Li Chen
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, Shandong, China.
| | - Xiangzhi Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China.
| |
Collapse
|
34
|
Gutiérrez G, Giraldo-Dávila D, Combariza MY, Holzgrabe U, Tabares-Guevara JH, Ramírez-Pineda JR, Acín S, Muñoz DL, Montoya G, Balcazar N. Serjanic Acid Improves Immunometabolic Markers in a Diet-Induced Obesity Mouse Model. Molecules 2020; 25:E1486. [PMID: 32218297 PMCID: PMC7181135 DOI: 10.3390/molecules25071486] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 02/06/2023] Open
Abstract
Plant extracts from Cecropia genus have been used by Latin-American traditional medicine to treat metabolic disorders and diabetes. Previous reports have shown that roots of Cecropia telenitida that contains serjanic acid as one of the most prominent and representative pentacyclic triterpenes. The study aimed to isolate serjanic acid and evaluate its effect in a prediabetic murine model by oral administration. A semi-pilot scale extraction was established and serjanic acid purification was followed using direct MALDI-TOF analysis. A diet induced obesity mouse model was used to determine the impact of serjanic acid over selected immunometabolic markers. Mice treated with serjanic acid showed decreased levels of cholesterol and triacylglycerols, increased blood insulin levels, decreased fasting blood glucose and improved glucose tolerance, and insulin sensitivity. At transcriptional level, the reduction of inflammation markers related to adipocyte differentiation is reported.
Collapse
Affiliation(s)
- Gustavo Gutiérrez
- Natural Sciences School, Pharmaceutical Sciences Department, Universidad Icesi, 760031 Cali, Colombia;
| | - Deisy Giraldo-Dávila
- School of Chemistry, Industrial University of Santander, 680003 Bucaramanga, Santander, Colombia; (D.G.-D.); (M.Y.C.)
| | - Marianny Y. Combariza
- School of Chemistry, Industrial University of Santander, 680003 Bucaramanga, Santander, Colombia; (D.G.-D.); (M.Y.C.)
| | - Ulrike Holzgrabe
- University of Würzburg, Institute for Pharmacy and Food Chemistry, 97074 Würzburg, Germany;
| | - Jorge Humberto Tabares-Guevara
- Grupo Inmunomodulación, School of Medicine, Universidad de Antioquia, 050010 Medellín, Antioquia, Colombia; (J.H.T.-G.); (J.R.R.-P.)
| | - José Robinson Ramírez-Pineda
- Grupo Inmunomodulación, School of Medicine, Universidad de Antioquia, 050010 Medellín, Antioquia, Colombia; (J.H.T.-G.); (J.R.R.-P.)
- Department of Physiology and Biochemistry, School of Medicine, Universidad de Antioquia, Carrera 51D Nº 62–29, 050010 Medellin, Colombia;
| | - Sergio Acín
- Department of Physiology and Biochemistry, School of Medicine, Universidad de Antioquia, Carrera 51D Nº 62–29, 050010 Medellin, Colombia;
- GENMOL Group. Sede de Investigación Universitaria, Universidad de Antioquia, Calle 62 # 52–59, 050010 Medellín, Colombia;
| | - Diana Lorena Muñoz
- GENMOL Group. Sede de Investigación Universitaria, Universidad de Antioquia, Calle 62 # 52–59, 050010 Medellín, Colombia;
| | - Guillermo Montoya
- Natural Sciences School, Pharmaceutical Sciences Department, Universidad Icesi, 760031 Cali, Colombia;
| | - Norman Balcazar
- Department of Physiology and Biochemistry, School of Medicine, Universidad de Antioquia, Carrera 51D Nº 62–29, 050010 Medellin, Colombia;
- GENMOL Group. Sede de Investigación Universitaria, Universidad de Antioquia, Calle 62 # 52–59, 050010 Medellín, Colombia;
| |
Collapse
|
35
|
Davis EM, Sandoval DA. Glucagon‐Like Peptide‐1: Actions and Influence on Pancreatic Hormone Function. Compr Physiol 2020; 10:577-595. [DOI: 10.1002/cphy.c190025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
36
|
da Rosa-Santos CA, da Costa Rodrigues P, Silva LR, Arantes VC, de Barros Reis MA, Colodel EM, Damazo AS, de Moura EG, Carneiro EM, Latorraca MQ. Early protein restriction increases intra-islet GLP-1 production and pancreatic β-cell proliferation mediated by the β-catenin pathway. Eur J Nutr 2020; 59:3565-3579. [PMID: 32076803 DOI: 10.1007/s00394-020-02192-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 01/28/2020] [Indexed: 12/25/2022]
Abstract
PURPOSE In the present study, we investigated whether intra-islet GLP-1 production and its modulation have a role in apoptosis, proliferation or neogenesis that is compromised by protein restriction during the foetal and suckling periods. METHODS Exendin-4, a GLP-1 receptor agonist (treated groups), or saline (non-treated groups) was intraperitoneally administered for 15 days from 75 to 90 days of age in female adult rats consisting of offspring born to and suckled by mothers fed a control diet (control groups) and who had the same diet until 90 days of age or offspring born to and suckled by mothers fed a low-protein diet and who were fed the control diet after weaning until 90 days of age (protein-restricted group). RESULTS The β-cell mass was lower in the protein-restricted groups than in the control groups. Exendin-4 increased β-cell mass, regardless of the mother's protein intake. The colocalization of GLP-1/glucagon was higher in the protein-restricted rats than in control rats in both the exendin-4-treated and non-treated groups. The frequency of cleaved caspase-3-labelled cells was higher in the non-treated protein-restricted group than in the non-treated control group and was similar in the treated protein-restricted and treated control groups. Regardless of treatment with exendin-4, Ki67-labelled cell frequency and β-catenin/DAPI colocalization were elevated in the protein-restricted groups. Exendin-4 increased the area of endocrine cell clusters and β-catenin/DAPI and FoxO1/DAPI colocalization regardless of the mother's protein intake. CONCLUSIONS Protein restriction in early life increased intra-islet GLP-1 production and β-cell proliferation, possibly mediated by the β-catenin pathway.
Collapse
Affiliation(s)
- Chaiane Aline da Rosa-Santos
- Mestrado em Nutrição, Alimentos e Metabolismo, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Priscila da Costa Rodrigues
- Mestrado em Nutrição, Alimentos e Metabolismo, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Luana Resende Silva
- Mestrado em Nutrição, Alimentos e Metabolismo, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Vanessa Cristina Arantes
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso (UFMT), Avenida Fernando Correa da Costa, 2367 Bairro Boa Esperança, Cuiabá, MT, 78060-900, Brazil
| | - Marise Auxiliadora de Barros Reis
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso (UFMT), Avenida Fernando Correa da Costa, 2367 Bairro Boa Esperança, Cuiabá, MT, 78060-900, Brazil
| | - Edson Moleta Colodel
- Departamento de Clínica Médica Veterinária, Faculdade de Agronomia e Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Amílcar Sabino Damazo
- Departamento de Ciências Básicas da Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Egberto Gaspar de Moura
- Laboratório de Fisiologia Endócrina, Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Everardo Magalhães Carneiro
- Departamento de Anatomia, Biologia Celular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Márcia Queiroz Latorraca
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso (UFMT), Avenida Fernando Correa da Costa, 2367 Bairro Boa Esperança, Cuiabá, MT, 78060-900, Brazil.
| |
Collapse
|
37
|
Exome sequencing revealed DNA variants in NCOR1, IGF2BP1, SGLT2 and NEK11 as potential novel causes of ketotic hypoglycemia in children. Sci Rep 2020; 10:2114. [PMID: 32034166 PMCID: PMC7005888 DOI: 10.1038/s41598-020-58845-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 12/31/2019] [Indexed: 12/11/2022] Open
Abstract
Unexplained or idiopathic ketotic hypoglycemia (KH) is the most common type of hypoglycemia in children. The diagnosis is based on the exclusion of routine hormonal and metabolic causes of hypoglycemia. We aimed to identify novel genes that cause KH, as this may lead to a more targeted treatment. Deep phenotyping of ten preschool age at onset KH patients (boys, n = 5; girls, n = 5) was performed followed by trio exome sequencing and comprehensive bioinformatics analysis. Data analysis revealed four novel candidate genes: (1) NCOR1 in a patient with KH, iron deficiency and loose stools; (2) IGF2BP1 in a proband with KH, short stature and delayed bone age; (3) SLC5A2 in a proband with KH, intermittent glucosuria and extremely elevated p-GLP-1; and (4) NEK11 in a proband with ketotic hypoglycemia and liver affliction. These genes are associated with different metabolic processes, such as gluconeogenesis, translational regulation, and glucose transport. In conclusion, WES identified DNA variants in four different genes as potential novel causes of IKH, suggesting that IKH is a heterogeneous disorder that can be split into several novel diseases: NCOR1-KH, IGF2BP1-KH, SGLT2-KH or familial renal glucosuria KH, and NEK11-KH. Precision medicine treatment based on exome sequencing may lead to advances in the management of IKH.
Collapse
|
38
|
Insulin Secretion Depends on Intra-islet Glucagon Signaling. Cell Rep 2019; 25:1127-1134.e2. [PMID: 30380405 DOI: 10.1016/j.celrep.2018.10.018] [Citation(s) in RCA: 215] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 06/11/2018] [Accepted: 10/02/2018] [Indexed: 12/20/2022] Open
Abstract
The intra-islet theory states that glucagon secretion is suppressed when insulin secretion is stimulated, but glucagon's role in intra-islet paracrine regulation is controversial. This study investigated intra-islet functions of glucagon in mice. We examined glucagon-induced insulin secretion using isolated perfused pancreata from wild-type, GLP-1 receptor (GLP-1R) knockout, diphtheria toxin-induced proglucagon knockdown, β cell-specific glucagon receptor (Gcgr) knockout, and global Gcgr knockout (Gcgr-/-) mice. We found that glucagon stimulates insulin secretion through both Gcgr and GLP-1R. Moreover, loss of either Gcgr or GLP-1R does not change insulin responses, whereas combined blockage of both receptors significantly reduces insulin secretion. Active GLP-1 is identified in pancreatic perfusate from Gcgr-/- but not wild-type mice, suggesting that β cell GLP-1R activation results predominantly from glucagon action. Our results suggest that combined activity of glucagon and GLP-1 receptors is essential for β cell secretory responses, emphasizing a role for paracrine intra-islet glucagon actions to maintain appropriate insulin secretion.
Collapse
|
39
|
Müller TD, Finan B, Bloom SR, D'Alessio D, Drucker DJ, Flatt PR, Fritsche A, Gribble F, Grill HJ, Habener JF, Holst JJ, Langhans W, Meier JJ, Nauck MA, Perez-Tilve D, Pocai A, Reimann F, Sandoval DA, Schwartz TW, Seeley RJ, Stemmer K, Tang-Christensen M, Woods SC, DiMarchi RD, Tschöp MH. Glucagon-like peptide 1 (GLP-1). Mol Metab 2019; 30:72-130. [PMID: 31767182 PMCID: PMC6812410 DOI: 10.1016/j.molmet.2019.09.010] [Citation(s) in RCA: 841] [Impact Index Per Article: 168.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 09/10/2019] [Accepted: 09/22/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The glucagon-like peptide-1 (GLP-1) is a multifaceted hormone with broad pharmacological potential. Among the numerous metabolic effects of GLP-1 are the glucose-dependent stimulation of insulin secretion, decrease of gastric emptying, inhibition of food intake, increase of natriuresis and diuresis, and modulation of rodent β-cell proliferation. GLP-1 also has cardio- and neuroprotective effects, decreases inflammation and apoptosis, and has implications for learning and memory, reward behavior, and palatability. Biochemically modified for enhanced potency and sustained action, GLP-1 receptor agonists are successfully in clinical use for the treatment of type-2 diabetes, and several GLP-1-based pharmacotherapies are in clinical evaluation for the treatment of obesity. SCOPE OF REVIEW In this review, we provide a detailed overview on the multifaceted nature of GLP-1 and its pharmacology and discuss its therapeutic implications on various diseases. MAJOR CONCLUSIONS Since its discovery, GLP-1 has emerged as a pleiotropic hormone with a myriad of metabolic functions that go well beyond its classical identification as an incretin hormone. The numerous beneficial effects of GLP-1 render this hormone an interesting candidate for the development of pharmacotherapies to treat obesity, diabetes, and neurodegenerative disorders.
Collapse
Affiliation(s)
- T D Müller
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany; Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany.
| | - B Finan
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN, USA
| | - S R Bloom
- Division of Diabetes, Endocrinology and Metabolism, Imperial College London, London, UK
| | - D D'Alessio
- Division of Endocrinology, Duke University Medical Center, Durham, NC, USA
| | - D J Drucker
- The Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, M5G1X5, Canada
| | - P R Flatt
- SAAD Centre for Pharmacy & Diabetes, Ulster University, Coleraine, Northern Ireland, UK
| | - A Fritsche
- German Center for Diabetes Research (DZD), Neuherberg, Germany; Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University of Tübingen, Tübingen, Germany; Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, Department of Internal Medicine, University of Tübingen, Tübingen, Germany
| | - F Gribble
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - H J Grill
- Institute of Diabetes, Obesity and Metabolism, Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - J F Habener
- Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Harvard University, Boston, MA, USA
| | - J J Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - W Langhans
- Physiology and Behavior Laboratory, ETH Zurich, Schwerzenbach, Switzerland
| | - J J Meier
- Diabetes Division, St Josef Hospital, Ruhr-University Bochum, Bochum, Germany
| | - M A Nauck
- Diabetes Center Bochum-Hattingen, St Josef Hospital (Ruhr-Universität Bochum), Bochum, Germany
| | - D Perez-Tilve
- Department of Internal Medicine, University of Cincinnati-College of Medicine, Cincinnati, OH, USA
| | - A Pocai
- Cardiovascular & ImmunoMetabolism, Janssen Research & Development, Welsh and McKean Roads, Spring House, PA, 19477, USA
| | - F Reimann
- Metabolic Research Laboratories and Medical Research Council Metabolic Diseases Unit, Wellcome Trust-Medical Research Council, Institute of Metabolic Science, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - D A Sandoval
- Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - T W Schwartz
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, DL-2200, Copenhagen, Denmark; Department of Biomedical Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark
| | - R J Seeley
- Department of Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - K Stemmer
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany; German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - M Tang-Christensen
- Obesity Research, Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | - S C Woods
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, USA
| | - R D DiMarchi
- Novo Nordisk Research Center Indianapolis, Indianapolis, IN, USA; Department of Chemistry, Indiana University, Bloomington, IN, USA
| | - M H Tschöp
- German Center for Diabetes Research (DZD), Neuherberg, Germany; Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany; Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| |
Collapse
|
40
|
Noguchi GM, Huising MO. Integrating the inputs that shape pancreatic islet hormone release. Nat Metab 2019; 1:1189-1201. [PMID: 32694675 PMCID: PMC7378277 DOI: 10.1038/s42255-019-0148-2] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 11/07/2019] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a complex mini organ composed of a variety of endocrine cells and their support cells, which together tightly control blood glucose homeostasis. Changes in glucose concentration are commonly regarded as the chief signal controlling insulin-secreting beta cells, glucagon-secreting alpha cells and somatostatin-secreting delta cells. However, each of these cell types is highly responsive to a multitude of endocrine, paracrine, nutritional and neural inputs, which collectively shape the final endocrine output of the islet. Here, we review the principal inputs for each islet-cell type and the physiological circumstances in which these signals arise, through the prism of the insights generated by the transcriptomes of each of the major endocrine-cell types. A comprehensive integration of the factors that influence blood glucose homeostasis is essential to successfully improve therapeutic strategies for better diabetes management.
Collapse
Affiliation(s)
- Glyn M Noguchi
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, CA, USA
| | - Mark O Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, CA, USA.
- Department of Physiology & Membrane Biology, School of Medicine, University of California, Davis, Davis, CA, USA.
| |
Collapse
|
41
|
Kim KS, Hutch CR, Wood L, Magrisso IJ, Seeley RJ, Sandoval DA. Glycemic effect of pancreatic preproglucagon in mouse sleeve gastrectomy. JCI Insight 2019; 4:129452. [PMID: 31619587 PMCID: PMC6824314 DOI: 10.1172/jci.insight.129452] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 09/18/2019] [Indexed: 02/06/2023] Open
Abstract
Intestinally derived glucagon-like peptide-1 (GLP-1), encoded by the preproglucagon (Gcg) gene, is believed to function as an incretin. However, our previous work questioned this dogma and demonstrated that pancreatic peptides rather than intestinal Gcg peptides, including GLP-1, are a primary regulator of glucose homeostasis in normal mice. The objective of these experiments was to determine whether changes in nutrition or alteration of gut hormone secretion by bariatric surgery would result in a larger role for intestinal GLP-1 in the regulation of insulin secretion and glucose homeostasis. Multiple transgenic models, including mouse models with intestine- or pancreas tissue-specific Gcg expression and a whole-body Gcg-null mouse model, were generated to study the role of organ-specific GLP-1 production on glucose homeostasis under dietary-induced obesity and after weight loss from bariatric surgery (vertical sleeve gastrectomy; VSG). Our findings indicated that the intestine is a major source of circulating GLP-1 after various nutrient and surgical stimuli. However, even with the 4-fold increase in intestinally derived GLP-1 with VSG, it is pancreatic peptides, not intestinal Gcg peptides, that are necessary for surgery-induced improvements in glucose homeostasis.
Collapse
|
42
|
Hutch CR, Roelofs K, Haller A, Sorrell J, Leix K, D'Alessio DD, Augustin R, Seeley RJ, Klein T, Sandoval DA. The role of GIP and pancreatic GLP-1 in the glucoregulatory effect of DPP-4 inhibition in mice. Diabetologia 2019; 62:1928-1937. [PMID: 31414143 PMCID: PMC6732043 DOI: 10.1007/s00125-019-4963-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/11/2019] [Indexed: 11/26/2022]
Abstract
AIMS/HYPOTHESIS Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are two peptides that function to promote insulin secretion. Dipeptidyl peptidase-4 (DPP-4) inhibitors increase the bioavailability of both GLP-1 and GIP but the dogma continues to be that it is the increase in GLP-1 that contributes to the improved glucose homeostasis. We have previously demonstrated that pancreatic rather than intestinal GLP-1 is necessary for improvements in glucose homeostasis in mice. Therefore, we hypothesise that a combination of pancreatic GLP-1 and GIP is necessary for the full effect of DPP-4 inhibitors on glucose homeostasis. METHODS We have genetically engineered mouse lines in which the preproglucagon gene (Gcg) is absent in the entire body (GcgRAΔNull) or is expressed exclusively in the intestine (GcgRAΔVilCre) or pancreas and duodenum (GcgRAΔPDX1Cre). These mice were used to examine oral glucose tolerance and GLP-1 and GIP responses to a DPP-4 inhibitor alone, or in combination with incretin receptor antagonists. RESULTS Administration of the DPP-4 inhibitor, linagliptin, improved glucose tolerance in GcgRAΔNull mice and control littermates and in GcgRAΔVilCre and GcgRAΔPDX1Cre mice. The potent GLP-1 receptor antagonist, exendin-[9-39] (Ex9), blunted improvements in glucose tolerance in linagliptin-treated control mice and in GcgRAΔPDX1Cre mice. Ex9 had no effect on glucose tolerance in linagliptin-treated GcgRAΔNull or in GcgRAΔVilCre mice. In addition to GLP-1, linagliptin also increased postprandial plasma levels of GIP to a similar degree in all genotypes. When linagliptin was co-administered with a GIP-antagonising antibody, the impact of linagliptin was partially blunted in wild-type mice and was fully blocked in GcgRAΔNull mice. CONCLUSIONS/INTERPRETATION Taken together, these data suggest that increases in pancreatic GLP-1 and GIP are necessary for the full effect of DPP-4 inhibitors on glucose tolerance.
Collapse
Affiliation(s)
- Chelsea R Hutch
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Karen Roelofs
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - April Haller
- Department of Internal Medicine-Endocrinology, Diabetes, and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Joyce Sorrell
- Department of Internal Medicine-Endocrinology, Diabetes, and Metabolism, University of Cincinnati, Cincinnati, OH, USA
| | - Kyle Leix
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - David D D'Alessio
- Division of Endocrinology, Metabolism, and Nutrition, Duke University Medical Center, Durham, NC, USA
| | - Robert Augustin
- Cardiometabolic Diseases Research (Biberach), Boehringer Ingelheim, Ingelheim am Rhein, Germany
| | - Randy J Seeley
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA
| | - Thomas Klein
- Cardiometabolic Diseases Research (Biberach), Boehringer Ingelheim, Ingelheim am Rhein, Germany
| | - Darleen A Sandoval
- Department of Surgery, University of Michigan, 2800 Plymouth Road, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
43
|
Holst JJ, Albrechtsen NJW, Rosenkilde MM, Deacon CF. Physiology of the Incretin Hormones,
GIP
and
GLP
‐1—Regulation of Release and Posttranslational Modifications. Compr Physiol 2019; 9:1339-1381. [DOI: 10.1002/cphy.c180013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
44
|
Smith NK, Hackett TA, Galli A, Flynn CR. GLP-1: Molecular mechanisms and outcomes of a complex signaling system. Neurochem Int 2019; 128:94-105. [PMID: 31002893 PMCID: PMC7081944 DOI: 10.1016/j.neuint.2019.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/26/2019] [Accepted: 04/15/2019] [Indexed: 12/15/2022]
Abstract
Meal ingestion provokes the release of hormones and transmitters, which in turn regulate energy homeostasis and feeding behavior. One such hormone, glucagon-like peptide-1 (GLP-1), has received significant attention in the treatment of obesity and diabetes due to its potent incretin effect. In addition to the peripheral actions of GLP-1, this hormone is able to alter behavior through the modulation of multiple neural circuits. Recent work that focused on elucidating the mechanisms and outcomes of GLP-1 neuromodulation led to the discovery of an impressive array of GLP-1 actions. Here, we summarize the many levels at which the GLP-1 signal adapts to different systems, with the goal being to provide a background against which to guide future research.
Collapse
Affiliation(s)
- Nicholas K Smith
- Vanderbilt Brain Institute, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Troy A Hackett
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Aurelio Galli
- Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Charles R Flynn
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
45
|
Yu CG, Fu Y, Fang Y, Zhang N, Sun RX, Zhao D, Feng YM, Zhang BY. Fighting Type-2 Diabetes: Present and Future Perspectives. Curr Med Chem 2019; 26:1891-1907. [PMID: 28990512 DOI: 10.2174/0929867324666171009115356] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/01/2017] [Accepted: 09/28/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Type-2 diabetes mellitus accounts for 80-90% of diabetic patients. So far, the treatment of diabetes mainly aims at elevating insulin level and lowering glucose level in the peripheral blood and mitigating insulin resistance. Physiologically, insulin secretion from pancreatic β cells is delicately regulated. Thus, how insulin-related therapies could titrate blood glucose appropriately and avoid the occurrence of hypoglycemia remains an important issue for decades. Similar question is addressed on how to attenuate vascular complication in diabetic subjects. METHODS We overviewed the evolution of each class of anti-diabetic drugs that have been used in clinical practice, focusing on their mechanisms, clinical results and cautions. RESULTS Glucagon-like peptide-1 receptor agonists stimulate β cells for insulin secretion in response to diet but not in fasting stage, which make them superior than conventional insulinsecretion stimulators. DPP-4 inhibitors suppress glucagon-like peptide-1 degradation. Sodium/ glucose co-transporter 2 inhibitors enhance glucose clearance through urine excretion. The appearance of these new drugs provides new information about glycemic control. We update the clinical findings of Glucagon-like peptide-1 receptor agonists, DPP-4 inhibitors and Sodium/glucose cotransporter 2 inhibitors in glycemic control and the risk or progression of cardiovascular disease in diabetic patients. Stem cell therapy might be an alternative tool for diabetic patients to improve β cell regeneration and peripheral ischemia. We summarize the clinical results of mesenchymal stem cells transplanted into patients with diabetic limb and foot. CONCLUSION A stepwise intensification of dual and triple therapy for individual diabetic patient is required to achieve therapeutic target.
Collapse
Affiliation(s)
- Cai-Guo Yu
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Ying Fu
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Yuan Fang
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Ning Zhang
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Rong-Xin Sun
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Dong Zhao
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Ying-Mei Feng
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| | - Bao-Yu Zhang
- Beijing Key Laboratory of Diabetic Prevention and Research, Department of Endocrinology, Lu He hospital, Capital Medical University, Beijing 100149, China
| |
Collapse
|
46
|
Chen X, Zhang J, Zhou Z. Targeting Islets: Metabolic Surgery Is More than a Bariatric Surgery. Obes Surg 2019; 29:3001-3009. [DOI: 10.1007/s11695-019-03979-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
|
47
|
Dusaulcy R, Handgraaf S, Visentin F, Howald C, Dermitzakis ET, Philippe J, Gosmain Y. High-fat diet impacts more changes in beta-cell compared to alpha-cell transcriptome. PLoS One 2019; 14:e0213299. [PMID: 30849121 PMCID: PMC6407777 DOI: 10.1371/journal.pone.0213299] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 02/19/2019] [Indexed: 12/27/2022] Open
Abstract
Characterization of endocrine-cell functions and associated molecular signatures in diabetes is crucial to better understand why and by which mechanisms alpha and beta cells cause and perpetuate metabolic abnormalities. The now recognized role of glucagon in diabetes control is a major incentive to have a better understanding of dysfunctional alpha cells. To characterize molecular alterations of alpha cells in diabetes, we analyzed alpha-cell transcriptome from control and diabetic mice using diet-induced obesity model. To this aim, we quantified the expression levels of total mRNAs from sorted alpha and beta cells of low-fat and high-fat diet-treated mice through RNAseq experiments, using a transgenic mouse strain allowing collections of pancreatic alpha- and beta-cells after 16 weeks of diet. We now report that pancreatic alpha cells from obese hyperglycemic mice displayed minor variations of their transcriptome compared to controls. Depending on analyses, we identified 11 to 39 differentially expressed genes including non-alpha cell markers mainly due to minor cell contamination during purification process. From these analyses, we identified three new target genes altered in diabetic alpha cells and potently involved in cellular stress and exocytosis (Upk3a, Adcy1 and Dpp6). By contrast, analysis of the beta-cell transcriptome from control and diabetic mice revealed major alterations of specific genes coding for proteins involved in proliferation and secretion. We conclude that alpha cell transcriptome is less reactive to HFD diet compared to beta cells and display adaptations to cellular stress and exocytosis.
Collapse
Affiliation(s)
- Rodolphe Dusaulcy
- Molecular Diabetes Laboratory, Division of Endocrinology, Diabetes, Hypertension and Nutrition, University Hospital/Diabetes Center/University of Geneva Medical School, Geneva, Switzerland
| | - Sandra Handgraaf
- Molecular Diabetes Laboratory, Division of Endocrinology, Diabetes, Hypertension and Nutrition, University Hospital/Diabetes Center/University of Geneva Medical School, Geneva, Switzerland
| | - Florian Visentin
- Molecular Diabetes Laboratory, Division of Endocrinology, Diabetes, Hypertension and Nutrition, University Hospital/Diabetes Center/University of Geneva Medical School, Geneva, Switzerland
| | - Cedric Howald
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Emmanouil T. Dermitzakis
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Jacques Philippe
- Molecular Diabetes Laboratory, Division of Endocrinology, Diabetes, Hypertension and Nutrition, University Hospital/Diabetes Center/University of Geneva Medical School, Geneva, Switzerland
| | - Yvan Gosmain
- Molecular Diabetes Laboratory, Division of Endocrinology, Diabetes, Hypertension and Nutrition, University Hospital/Diabetes Center/University of Geneva Medical School, Geneva, Switzerland
- * E-mail:
| |
Collapse
|
48
|
Abstract
The organs require oxygen and other types of nutrients (amino acids, sugars, and lipids) to function, the heart consuming large amounts of fatty acids for oxidation and adenosine triphosphate (ATP) generation.
Collapse
|
49
|
Maczewsky J, Kaiser J, Gresch A, Gerst F, Düfer M, Krippeit-Drews P, Drews G. TGR5 Activation Promotes Stimulus-Secretion Coupling of Pancreatic β-Cells via a PKA-Dependent Pathway. Diabetes 2019; 68:324-336. [PMID: 30409782 DOI: 10.2337/db18-0315] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 10/31/2018] [Indexed: 11/13/2022]
Abstract
The Takeda-G-protein-receptor-5 (TGR5) mediates physiological actions of bile acids. Since it was shown that TGR5 is expressed in pancreatic tissue, a direct TGR5 activation in β-cells is currently postulated and discussed. The current study reveals that oleanolic acid (OLA) affects murine β-cell function by TGR5 activation. Both a Gαs inhibitor and an inhibitor of adenylyl cyclase (AC) prevented stimulating effects of OLA. Accordingly, OLA augmented the intracellular cAMP concentration. OLA and two well-established TGR5 agonists, RG239 and tauroursodeoxycholic acid (TUDCA), acutely promoted stimulus-secretion coupling (SSC). OLA reduced KATP current and elevated current through Ca2+ channels. Accordingly, in mouse and human β-cells, TGR5 ligands increased the cytosolic Ca2+ concentration by stimulating Ca2+ influx. Higher OLA concentrations evoked a dual reaction, probably due to activation of a counterregulating pathway. Protein kinase A (PKA) was identified as a downstream target of TGR5 activation. In contrast, inhibition of phospholipase C and phosphoinositide 3-kinase did not prevent stimulating effects of OLA. Involvement of exchange protein directly activated by cAMP 2 (Epac2) or farnesoid X receptor (FXR2) was ruled out by experiments with knockout mice. The proposed pathway was not influenced by local glucagon-like peptide 1 (GLP-1) secretion from α-cells, shown by experiments with MIN6 cells, and a GLP-1 receptor antagonist. In summary, these data clearly demonstrate that activation of TGR5 in β-cells stimulates insulin secretion via an AC/cAMP/PKA-dependent pathway, which is supposed to interfere with SSC by affecting KATP and Ca2+ currents and thus membrane potential.
Collapse
Affiliation(s)
- Jonas Maczewsky
- Institute of Pharmacy, Department of Pharmacology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Julia Kaiser
- Institute of Pharmacy, Department of Pharmacology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Anne Gresch
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, University of Münster, Münster, Germany
| | - Felicia Gerst
- Institute for Diabetes Research and Metabolic Diseases, Helmholtz Center Munich, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Martina Düfer
- Institute of Pharmaceutical and Medicinal Chemistry, Department of Pharmacology, University of Münster, Münster, Germany
| | - Peter Krippeit-Drews
- Institute of Pharmacy, Department of Pharmacology, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Gisela Drews
- Institute of Pharmacy, Department of Pharmacology, Eberhard Karls University of Tübingen, Tübingen, Germany
| |
Collapse
|
50
|
Chepurny OG, Matsoukas MT, Liapakis G, Leech CA, Milliken BT, Doyle RP, Holz GG. Nonconventional glucagon and GLP-1 receptor agonist and antagonist interplay at the GLP-1 receptor revealed in high-throughput FRET assays for cAMP. J Biol Chem 2019; 294:3514-3531. [PMID: 30622136 DOI: 10.1074/jbc.ra118.005682] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 01/05/2019] [Indexed: 12/13/2022] Open
Abstract
G protein-coupled receptors (GPCRs) for glucagon (GluR) and glucagon-like peptide-1 (GLP-1R) are normally considered to be highly selective for glucagon and GLP-1, respectively. However, glucagon secreted from pancreatic α-cells may accumulate at high concentrations to exert promiscuous effects at the β-cell GLP-1R, as may occur in the volume-restricted microenvironment of the islets of Langerhans. Furthermore, systemic administration of GluR or GLP-1R agonists and antagonists at high doses may lead to off-target effects at other receptors. Here, we used molecular modeling to evaluate data derived from FRET assays that detect cAMP as a read-out for GluR and GLP-1R activation. This analysis established that glucagon is a nonconventional GLP-1R agonist, an effect inhibited by the GLP-1R orthosteric antagonist exendin(9-39) (Ex(9-39)). The GluR allosteric inhibitors LY2409021 and MK 0893 antagonized glucagon and GLP-1 action at the GLP-1R, whereas des-His1-[Glu9]glucagon antagonized glucagon action at the GluR, while having minimal inhibitory action versus glucagon or GLP-1 at the GLP-1R. When testing Ex(9-39) in combination with des-His1-[Glu9]glucagon in INS-1 832/13 cells, we validated a dual agonist action of glucagon at the GluR and GLP-1R. Hybrid peptide GGP817 containing glucagon fused to a fragment of peptide YY (PYY) acted as a triagonist at the GluR, GLP-1R, and neuropeptide Y2 receptor (NPY2R). Collectively, these findings provide a new triagonist strategy with which to target the GluR, GLP-1R, and NPY2R. They also provide an impetus to reevaluate prior studies in which GluR and GLP-1R agonists and antagonists were assumed not to exert promiscuous actions at other GPCRs.
Collapse
Affiliation(s)
| | | | - George Liapakis
- the Department of Pharmacology, School of Medicine, University of Crete, 71003 Heraklion, Crete, Greece, and
| | | | - Brandon T Milliken
- the Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - Robert P Doyle
- From the Departments of Medicine, .,the Department of Chemistry, Syracuse University, Syracuse, New York 13244
| | - George G Holz
- From the Departments of Medicine, .,Pharmacology, State University of New York (SUNY), Upstate Medical University, Syracuse, New York 13210
| |
Collapse
|